This article constructs the profit rate formula from the perspective of price, and proves that inflation can increase the profit rate. Further analysis found that inflation is an important way for capital to maintain and increase surplus value. However, the realization of profit rate is not easy. Financial innovation improves the path to achieving profit rate through debt accumulation, slows down the decline in profit rate, and maintains economic prosperity. However, this will promote the relative excess of corporate and private debt. While financial innovation will promote the growth of wealth (debt), it will also widen the gap between the rich and the poor. The growth of wealth requires the support of higher profit margins, which slows down the accumulation of capital, strengthens the two-way fluctuations in wealth and profit rate, and makes the economic and financial crisis more likely to occur. In addition, profit rate can also be used as a basic theory to explain various types of inflation.