How can they immigrate to Australia with skills and how can they verify their so-called work experience?

You need a certificate from the company or unit indicating how long you have worked in any position in the company or unit.

Australian skilled immigrant visa

Skilled immigrants refer to applicants applying for immigration by virtue of their academic qualifications, IELTS scores, vocational skills and other skills. Australian skilled immigrant 189, skilled immigrant 190, visa 489. All three kinds of visas require applicants to have at least four IELTS scores of 6, the occupation appears on the SOL occupation list, and the immigration score is above 60.

Australian employer sponsored work visa

There are three kinds of visas for Australian employers to sponsor immigrants, namely, visa 457, visa 186 and visa 187. Each visa requires the applicant to obtain an IELTS certificate and can meet the requirements and skills of the nominated occupation. The premise of applying for employer-sponsored immigration is to be nominated by an Australian employer, but the Immigration Bureau attaches great importance to the qualifications of the employer and whether there is a bad visa record. It is not easy for applicants to find a compliant company.

First of all, you have to determine your visa type!