The valve is a valve mechanism main component, it is to ensure that the engine obtains good economic performance,dynamic performance, reliability and durability important parts. A lot of practice indicate, thermal overload is the cause of the failure of valve is the main reason. This paper conducts a simulation of working process of the R3105T3 four - stroke diesel engines of Shandong Weituo Group Co.Ltd.as an example with the Matlab analysis software.Through the simulation, indictor diagram and transient heat transfer coefficient are computed .It proposes a simulation method to compute heat transfer and deformation of the exhaust vavle.And with this method, it can predict the engine indictor diagram and describe the heat transfer situation of the exhaust valve as well as temperature distribution. So it can prevent losing efficacy of the exhaust vavle by choosing resonable related parameters. Meanwhile this article conducts heat transfer simulation and analysis of the exhaust vavle under different working conditions.