The present disclosure relates to power-assisted steering systems and mobile inspection devices. Implementations may include and/or involve a directional control valve, a second hydraulic pump and a first driving motor. When determining an engine on a chassis has not been started, a central control unit may control start of the first driving motor according to a received travelling instruction such that the first driving motor drives the second hydraulic pump and then the power-assisted steering motor can be driven through a second oil path of the second hydraulic pump. Accordingly, the power-assisted steering system can be driven to operate when the mobile inspection device is in operation and the engine on chassis is not started, thus it is possible to drive the power-assisted steering system without the chassis engine operating.