In view of the problems such as poor time efficiency, low accuracy and difficulty in judging the decline types of the existing decline parameters, a series of methods for “Production-Cumulative Production” is proposed to judge the decline types and fit the decline parameters based on the Arps decline equation. The fitting decline parameters is carried out according to three kinds of decline method, including exponential decline, hyperbolic decline, and harmonic decline, the hyperbolic decline adopts the trial-and-error method, and the fitting parameters, decline parameters and precision test parameters are calculated. In order to compare the fitting accuracy with other series of methods for “Production-Time” and bivariate regression method, two indexes of correlation and residual are selected to characterize the fitting accuracy. The results show that the correlation degree and residual of the “Production-Cumulative Production” series of methods are ideal, and the fitting accuracy is higher. Compared with the “Production-Time” series of methods and bivariate regression method, the decline index n is a trial-and-error parameter, and the n value can be controlled between 0 and 1. The parameters obtained by the bivariate regression method are inferior to those obtained by the series of methods for “Production-Cumulative Production” and “Production-Time” in terms of correlation and residual index. This method can analyze the actual development by fitting the decline parameters of various methods and analogy with the decline parameters of adjacent blocks, which can provide a new basis for the judgment of the decreasing type of oilfield and the comprehensive selection of decline parameters in the future.