The utility model discloses a pressure balance mechanism for a personnel air lock. The pressure balance mechanism for the personnel air lock is arranged on a frame (10) of the personnel air lock, and comprises a balance valve component, a balance valve drive component and a pressure balance pipeline component, wherein the balance valve drive component is arranged at the lower end of the balance valve component and used for driving the balance valve component to be opened, and the pressure balance pipeline component is arranged at the upper end of the balance valve component; the tail end of the balance pipeline component penetrates through the interior of a personnel air lock cabin through a through hole (18) in the frame (10); the junction of the pressure balance pipeline component and the through hole (18) in the frame (10) is provided with a pipeline sealing component; the pipeline sealing component is provided with a sealing detection joint (2), which is used for sealing detection on the pressure balance pipeline component and the balance valve component. By adopting the balance mechanism disclosed by the utility model, before the personnel air lock is unlocked, the pressure balance valve is opened, so that the air at both sides of the personnel air lock is communicated, and the goal that the pressure in the personnel air lock cabin and the pressure outside the personnel air lock is balanced is achieved; the pressure balance mechanism is simple and compact in structure and high in operating efficiency.