Effect of heating process with a designed heating rate on the austenite grain growth behavior of the as-cast 30Cr2Ni4MoV steel was studied, which aims to simulate the actual heating process during production of large-sized forging. The results show that for a fixed holding time the average size of austenitic grains increases exponentially with the increasing heating temperature; for a fixed heating temperature the average size of austenite grains changes approximate parabolically with the increasing holding time; when the heating temperature is increased to 1100℃, the grains grow up sharply; The Beck equation which describes the dependence of the average size of austenite grains on holding time during heating process of the as-cast 30Cr2Ni4MoV steel was acquired and models of the grain growth under the conditions of isothermal and non-isothermal respectively were also established.