Abstract: The temperature raise of KTP crystal with intracavity doubling frequency would greatly influence the performance and characteristic of the LD pumped all-solid-state green laser.In order to improve performance of laser,interior temperature field distribution of KTP crystal must be accurately controlled.Through completely work feature analysis of KTP crystal in the (Nd:YVO4/KTP) green laser,the thermal model according to the practicality is built,the general solution of a quadrate KTP crystal interior temperature distribution is obtained by an analytical thermal analysis method.As the quadrate thermal model is almost identical with laser,the deduced results will be more reasonable.The research results express that the KTP crystal maximal temperature raise according to the quadrate thermal mode is higher than the maximal temperature raise with the cylindrical thermal mode.The research provides a theoretical foundation for phase mismatching induced by non-uniform temperature raise,and play instructive effect in the improvement the performance of the Nd:YVO4/KTP green laser.