A footrest mechanism, comprising a chair support body, a locking component and a leg component. The locking component comprises a locking rod, a locking arm and a locking elastic member. The locking rod is pivotally connected to the chair support structure. The locking arm is pivotally connected to the leg component and the locking rod, respectively. The locking elastic member is connected to the chair support structure and the locking arm, respectively. The locking arm can be locked to the chair support structure to define a locking state and the locking state can be maintained due to an elastic deformation of the locking elastic member. The leg component is pivotally connected to the chair support structure and in a transmission connection with a driving component, and the leg component is capable of rotating relative to the chair support structure when the leg component is driven by the driving component.