Between 1981 and 2021, this research work looked at the test for equality of regression models employing some service expenditures on the Nigerian GDP. This study has five particular objectives that were created and used. Relevant related literatures were reviewed based on the factors in the objectives. This study used secondary data acquired from the National Bureau of Statistics and the Central Bank of Nigeria statistical bulletin, which included 46 activity sectors. The data was analyzed using multiple regression models. MINITAB 16 and Microsoft Excel 2010 were used for all calculations. The series plot results for each service expenditures indicate an upward trend for the whole plot, implying a linear link between expenditures and Nigeria's total GDP. To find the significant parameters and test for model equality, the Durbin method of estimating a multiple regression model was used; this revealed that all of the models' parameters estimates were not significant at 5%, which appears biased. Model (1), the Military Government Period Model, was found to be the "best" of the three regression models, with the highest R2 and Adj. R2 values of 99.8%, the smallest AIC and BIC values of 170.356 and 174.134, and the highest F-value of 4494.669 determined. According to the findings, the government should devote a smaller amount of its budget to recurrent spending and focus more on capital spending, such as agriculture, education, and health, as it is the primary driver of economic growth.