Based on the “Three Policies-in-One” macroeconomic policy theory, this paper calculates the macroeconomic policy index, TPIO. (M1–3)By constructing a VAR model, this paper empirically examines the dynamic relationship between GDP growth and the M1, M2 and M3. The research finds that there is a long-term equilibrium relationship between the first-order stationary GDP growth rate and the TPIO index, especially the stability policy efficiency index, which has the most significant and positive impact on the GDP growth rate. In contrast, the monetary policy space index and the fiscal policy space index do not have an insignificant impact on the GDP growth rate. In a nut shell, enhancing the coordination and effectiveness of related policies and boosting the efficiency of stable policies, are crucial for promoting economic growth. From this perspective, the TPIO is effective to some extent, but it primarily relies on the pillar of stable policy efficiency.