The invention discloses an automatic 
simulation test method for port impedance, which comprises the following steps of: sequentially applying 
voltage to each port of a tested circuit, solving corresponding port current, and further calculating the equivalent impedance of each port according to the 
Ohm law. The port impedance automatic 
simulation test method comprises the following steps: firstly, setting an active device in a tested circuit to be zero, and distributing a unique and fixed 
network identification number to each terminal of the tested circuit; then, listing a 
test sequence according to 
test requirements; and furthermore, introducing an independent 
voltage source specially used for measuring circuit port impedance into the circuit 
simulation diagram, and distributing 
network identification numbers to positive and negative terminals of the circuit simulation diagram according to a 
test sequence. Through matching 
network identification numbers of the independent 
voltage source terminal and the tested circuit terminal, 
electrical connection is realized. According to the invention, the efficiency of obtaining the impedance value is improved. Meanwhile, errors caused by manual analysis or calculation errors are avoided, and the accuracy of the obtained port impedance value is improved.