Considering the influence of temperature and pressure on the measurement of the partial pressure of oxygen using TDLAS technology, a temperature and pressure compensation algorithm for laser oxygen partial pressure sensors is proposed for eliminating these effects. The laser oxygen partial pressure sensor was constructed using an analog circuit, and the measured second-harmonic peak, temperature, and pressure values were uploaded to the master computer through an electrical connector, which performed temperature and pressure compensation using the BP neural network temperature and a pressure compensation algorithm to obtain accurate oxygen partial pressure values. The experimental results show that the algorithm can achieve compensation for the measured partial pressure of oxygen, and that the error of the partial pressure of the oxygen measurement is less than ±1 kPa, which meets the requirements of aerospace, aviation and other fields, and has a desirable application prospect.