The rectifier and filter simulation circuit based on Multisim is designed，it can avoid the inconvenience and potential danger of changing components in the actual circuit，and it can help study the rectifier and filter more thoroughly．By setting up the simulation circuit and adjusting the parameters of relevant devices，the waveform of rectifier filter is presented intuitively，the reason for the difference between voltage and theoretical value after rectifier is analyzed，and the conclusion is drawn that the filter effect is better with the larger capacitor value，and when the capacitor charge-discharge time constant is greater than 1 second，the output voltage reaches the maximum value．