Time delay is an inevitable factor in the activecontrol loop. This paper studies the delayed switching control of an inverted single pendulum on a cart, by using the delayed nonlinear swing up control and the delayed linear cascade PD stability control. To analyze the delay effect on the transient timedomain performance of the system, the derivative of the Lyapunov function at a specific moment of motion is linearized, and a simple criterion is then proposed for judging the transient performance based on the derivative. It is found that the time delay can decrease the energy input rate of the swing up control, and hence improve the transient performance. The definite integral method is then used to study the stability of the single pendulum, and the stable interval of the delay value is obtained. Case study shows that, with considering the delay effect of both the swing up control and the stability control, an appropriate timedelay value can be identified to improve the control performances for both transient and stability performance of the system.