The whole-process transient radiative transfer model of Gaussian pulse laser in anisotropic scattering medium is established using Monte Carlo method, then the probabilistic model of scattering direction is constructed and the process of coordinate system transformation is deduced. On the basis above, the temporal distribution and differences of Gaussian pulse laser echo characteristic is calculated and analyzed. Research result shows that pulsed increase/decrease of temporal echo signal is from the conversion of other signal categories and ahead or lag of itself; with the forward scattering enhancing, target-echo signal intensity increases, peak time forwards and temporal broadening weakens, while scatter- echo signal responses are in contrast and change weakly; target- echo characteristic associates with [0°, 90°] forward scattering region directly, as well as scatter-echo characteristic associating with [90° , 180° ] backward scattering region. The conclusion can provide theoretical guidance for performance improvement of active detection systems by pulse laser and anti-stealth detection of ground objects.