The invention provides a method for testing single parameters of a
gas compressor. The method comprises the following steps: determining the single parameters of the
gas compressor to be tested; multiple adjustment tests of single parameters are carried out, the total pressure ratio of the
gas compressor is kept stable through the gas compressor isobaric ratio
automatic control method, and the gas compressor isobaric ratio
automatic control method comprises the following steps that a target pressure ratio set value is determined; the compressor inlet total pressure and the compressor outlet total pressure are collected in real time, and a pressure ratio feedback value is calculated; calculating the deviation between the pressure ratio feedback value and the target pressure ratio set value; calculating a control output value by taking the deviation as an input quantity by using a PID
algorithm; and controlling the opening degree of the
exhaust valve according to the target pressure ratio set value, the pressure ratio feedback value, the deviation and the control output value. According to the method, for the
single parameter test of the engine, it is guaranteed that the
environment variable, namely the pressure ratio, is not changed in the one-way parameter test process, the influence of the variable, namely the pressure ratio, is eliminated, and more accurate
test data are obtained.