The Gaofen-14 （GF-14） satellite is equipped with a three-beam laser altimeter system aimed at assisting the two linear-array optical camera to perform global 1∶10 000 mapping without ground control points. Owing to mechanical vibration and environmental changes， the geometric parameters of the laser altimeter would deviate from those measured in the laboratory； thus， it is necessary to perform high-precision on-orbit geometric calibration. In this study， a strict geometric model of the laser footprint was constructed according to the characteristics of the GF-14 laser load. Through atmospheric correction and tidal correction， the laser spot captured by the ground detector array was used to perform on-orbit geometric calibration and accuracy verification. The test results indicate that the elevation accuracies of the GF-14 three-beam laser altimeter are 0.190， 0.256， and 0.220 m， which satisfy the design target and can be used as the elevation control point for operational production.