A scan driving circuit is disclosed, and the scan driving circuit has a pull-up control module, a pull-up module, a pull-down module, a pull-down maintaining module, a bootstrap capacitor and a constant low-level voltage source; the pull-up control module is connected to the pull-up module, the pull-down module, the pull-down maintaining module and the bootstrap capacitor respectively, and the constant low-level voltage source is connected to the pull-down maintaining module and the pull-down module respectively. The electrical leakage phenomenon can be efficiently avoided, and the reliability of the scan driving circuit is thus improved.