As a postdoctoral fellow in an American university, the professor agreed to apply for a work visa. Do I have to apply for returning to China?

Instructions for applying for a work visa

H, L, O, P and Q visas are work visas in the United States. All these visas require American companies or other institutions that intend to hire applicants to obtain the approval of the US Immigration Service before they can hire foreign employees. If approved, the employing company will issue an I-797 form to the applicant, allowing him to apply for a visa.

H visa:

H visas are issued to applicants who work in the United States for a short period of time. There is no visa fee for this visa. The approval letter must be approved by the US Immigration Service. If the applicant applies for a US work visa in China, he/she must wait until the embassy receives the I- 129 and I-797 approval forms from the Immigration Bureau before applying for a visa. If the applicant changes his identity in the United States, his approval letter does not need to be sent from the immigration office to the embassy, but when applying for a visa, the applicant must show the original I-797 form. All applicants must present the original approval letter from the Immigration Bureau during the interview, detailing the documents that they will work in the United States, as well as previous work certificates and academic qualifications.

L visa:

L visas are issued to people who will be sent to work in American branches or related companies. Applicants must hold management positions in the United States, or have specialized knowledge, and have worked for the same employer or company for at least one year in the three years before applying for a visa. The visa is valid for 2 years 1 time, and the visa fee is free. It is valid for multiple times within 2 years, and the visa fee is RMB 1080 yuan (USD 120 yuan). L visa approval must first be approved by the us immigration service. After the embassy receives the I-797 and I- 129 forms sent by the Immigration Bureau, the applicant can apply for a visa at the visa office. Applicants must produce documents detailing their work in the United States, as well as previous work certificates and academic qualifications. If the applicant applies for a visa specially approved by the company L- 1 (BlankETL- 1), he must show the original and three copies of the I-797 form. The original will be returned to the applicant after the visa is approved.

O, p and q visas:

These visas are issued to performers or professionals with special talents who go to the United States to perform, teach or participate in cultural exchange activities. The applicant's work unit in China and the host in the United States must contact the US Immigration Service. After being approved, the applicant can apply for a visa at the visa office. A-3: A-3 visa: issued to waiters, servants and other private employees of foreign government officials holding A visas. The A-3 visa is valid for 12 months, and the visa fee is free. Applicants are required to submit their passports, diplomatic notes to prove their employer's identity, completed application form-156 and two 2-inch photos by express delivery. In addition, the applicant also needs to submit the contract signed by the employer and the employee, detailing the employment relationship between the two parties during their stay in the United States, the reasonable employment period and documents proving that the employee is competent for the work to be done. All applicants for A-3 visas must prove that they have inseparable social, economic and family ties, so as to ensure that they must return to China after working for an American employer.