Firstly, the operation principles of peak holding circuits such as voltage and transconductance types are introduced. The factors influencing the precision of transconductance peak holding circuit are simulated and analyzed by Multisim9. The accuracy holding is greatly influenced by the choosing of peak holding capacitance. Then the simplified reference formula for choosing the capacitance values is given. Finally, experiments show that the transconductance peak holding circuit with MAX436 as design core has higher peak holding accuracy.