The invention relates to an autonomous navigation and attitude measurement device for a high speed train, which comprises a triaxial fiber-optic gyroscope, a triaxial accelerometer, a navigational computer, a temperature control circuit board, a power amplifying circuit board and a power supply module. The triaxial fiber-optic gyroscope and the triaxial accelerometer are fixedly connected onto a carrier, so that a strapdown inertial navigation system is free from a structural platform to provide a reference to measure specific force for the accelerometer, but adopts an immediate correcting strapdown matrix as a platform. The navigational computer collects a carrier coordinate system acceleration and angular speed information output by the fiber-optic gyroscope and the accelerometer, and attitude angle information, speed and position information of the carrier are immediately corrected singly through transformation of coordinates, the strapdown matrix, speed and the position matrix. The device is simple in structure, good in stability and high in precision.