The invention discloses a low calculating quantity global position system (GPS) positioning method based on second-order extended Kalman. The method includes the following steps of acquiring positioning results at the local k-1 moment, and calculating a priori estimate state quantity and a priori estimate error covariance at the current k moment; establishing an estimating equation of observed quantities; calculating a Kalman gain K; and calculating a positioning result and an error covariance at the current k moment. According to the low calculating quantity GPS positioning method based on the second-order extended Kalman, performances of second-order extended Kalman filter (EKF2) are achieved, simultaneously, calculating quantities are reduced, and the method is suitable for low-end hardware.