Abstract: In this paper,the Gompertz model and linear statistical method are used to analyze the growth factor of batch experiments for a liquid rocket engine.The reliability distribution of a new product is also forecasted.Then,Bayesian method is used to evaluate the reliability parameters of the products.In the article,first,the reliability growth analysis model is presented.Then with the reliability growth test data, a dynamic parameter iterative evaluation model is built.With the iterative model and field test data,the reliability evaluation of every stage can be calculated by Bayesian formula.Based on the distribution of function of the random variable,the reliability evaluation is given.An example is shown to illustrate this method.