In order to describe accurately laser heterodyne interferometer measurement in fast ultra-precision, a new model is proposed. The laser heterodyne interferometer measurement theory is analyzed, and laser interferometer fast ultra-precision model based on the Doppler frequency shift model is deduced. In the model, the integral of v2/c is added, the part is ignored in laser heterodyne interferometer conventional model. With this model, when the highest measurement speed is up to 1 m/s and the displacement is up to 3 m, about 18 nm of measurement error is reduced, and the residual error is removed, the fast ultra-precision measurement is realized.