The invention relates to an opposite-pole parallelism measuring system of a quadrupole mass analyzer. The system includes a pedestal, a sensor mechanism arranged on the pedestal, a clamp which clamps the quadrupole mass analyzer, a linear driving mechanism driving feeding of the clamp and a data processing mechanism; the sensor mechanism comprises a measuring rod and a capacitance sensor assembly, and the capacitance sensor assembly comprises a pair of symmetrical capacitance sensor probes; measuring values of the capacitance sensor probes are numbered in the sequence of sampling time; the data processing module calculates and measures indication difference x1i and screens a maximal value and a minimal value, and the parallelism, f13=x1max-x1min, between poles is calculated; and the data processing module determines whether the parallelism f13 of the poles is within a parallelism acceptance value f0 range, and is no, alarm is raised. The system of the invention has the advantages that the device is simple in structure and a measurement result is highly stable.