Constructing an intertemporal investment decision model, using CHFS micro data and related macro data, this paper studies the impact of money supply changes on households financial participation and risk asset holding ratio based on the interest rate channel. The theoretical analysis shows that when the increase of money supply leads to the decrease of money market interest rate, the financial participation and the proportion of risk assets held by all kinds of risk-prone households will increase. The empirical results show that the influence of money supply changes on money market interest rate is weak, and the interest rate channel may be blocked. Through the interest rate channel, the change in money supply has a partial mediating effect on the financial participation and the proportion of risk assets held by risk-loving households, but has a complete mediating effect on the risk-averse households.