The modelling of the LECGaSb crystal growth process was established by using the finite element simulation software. The influence of crystal rotation, crucible rotation, heat shield etc. on the solidliquid interface morphology of GaSb was analyzed. The results show that the rotation of the crystal and the rotation of the crucible have the effect of increasing and decreasing the curvature of the interface, and the rotation of the crucible has a greater influence on the surface morphology under the same rotating speed condition. In addition, reducing the angle of the shoulder and removing the heat shield have a role in reducing the curvature of the solidliquid interface; and the using of encapsulant increases the curvature of the solidliquid interface. The crucible has a certain position in the heater, at which the axial gradient of the melt is the largest. In the furnace, the most intense flow rate of Argon gas is in the area between the pulling bar and the heat shield. Argon gas convection leads to an increase in the upper furnace temperature and the decrease of the surface temperature of the GaSb melt about 8 ℃.