The invention discloses a curve fitting based gas pressure and micro-water content measurement method, which comprises the following steps of: 1) collection; 2) calibration; and 3) testing. According to the invention, measured experimental data are subjected to curve fitting by means of a laser gas spectrum absorption circuit, the gas pressure and the micro-water content information in gas are extracted from a curve subjected to fitting, two important indexes, namely, the micro-water content information in gas and the gas pressure, for judging whether electrical equipment is safe are accurately measured, and because the measurement of gas pressure is implemented without using a test instrument, the influence of testing on electrical equipment is maximumly reduced. Meanwhile, according to the invention, data can be acquired in real time, and the normal operation of extra-high voltage electrical equipment is ensured.