The invention relates to the technical field of 
medical instruments, and particularly discloses a 
voltage compensation method based on a medical vacuum negative pressure 
machine. The method comprises the steps of: setting a standard 
voltage value; collecting 
current voltage values of different circuits; judging whether the negative pressure 
machine performs first collection or not according to a first collection air pressure mark; determining a 
voltage difference value addition and subtraction mark according to the first collection air pressure mark, the standard voltage value and the 
current voltage values; determining a compensation value according to the first collection air pressure mark, the voltage difference value addition and subtraction mark, the standard voltage value and the 
current voltage values; and automatically correcting the current voltage values according to the voltage difference value addition and subtraction mark and the compensation value to obtain a final voltage value. According to the 
voltage compensation method, the consistency of the working voltage of the air 
pressure sensor can be ensured, so that the consistency of the upper and lower limits of the exhaust air pressure of the negative pressure 
machine is ensured; and meanwhile, manual repeated testing of the upper and lower limits of the air pressure value and code modification and burning are replaced by uniform code burning, so that the manpower and 
time cost is effectively reduced.