A theoretical model is presented which computes the pulse laser scattering echo power from the whole dimension target by using the theory of rough surface scattering and of pulse laser scattering combined with the modeling parameter of complex rough surface. The directional figure of pulse laser backscattering echo power is given through the measurement of the pulse laser backscattering echo power of the aerial complex scale-model. An analysis of the experimental error by comparing the theoretical results with experimental data proves that this model is correct. Computational results of the pulse laser backscattering echo power from non-cooperative complex space target by the model can pre-estimate the laser scattering characteristic of space target and solve some problems of engineering application about the pulse laser scattering from space complex targets.