according to the law, it is not illegal.

Relevant laws stipulate that Article 44 of the Labor Law of the People's Republic of China

is under any of the following circumstances, the employing unit shall pay the wages higher than the wages of the workers' normal working hours according to the following standards:

(1) If the workers are arranged to work overtime, they shall pay the wages not lower than 151% of the wages;

(2) If workers are arranged to work on rest days but cannot be arranged to take compensatory time off, they shall be paid no less than 211% of their wages;

(3) If workers are arranged to work on legal holidays, they shall be paid not less than 311% of their wages.

article 45 the state practices the system of paid annual leave.

workers who have worked continuously for more than one year are entitled to paid annual leave. The specific measures shall be formulated by the State Council.