Is it illegal for property workers to go to work in small supermarkets?

Illegal. It is against the labor law for an employer to arbitrarily change the post of an employee without the consent of the employee, so it is illegal for the property to open a supermarket in a small place and transfer its capital to the supermarket where the property staff work. Post adjustment is the main content of changing the labor contract, and the employer must negotiate with the laborer first.