In this paper, function P(x)=1/(A+Bx)+C is the approximation solution of the ordinary differential equation dy/dx=f(x,y),y(x₀)=y₀. With the integral applied, a new numerical method of ordinary differential equation is proposed. It is a stable explicit one step method for soving ordinary differential equation. The most impotant thing is that it is stable when the method is applied to the test eqution dy/dx=λy，y(0)=y₀(λ<0). The numerical experiments show that the method is effective.