The invention provides a semi-soft robot module with a stiffness keeping function and a semi-soft robot. The module mainly comprises a left airbag, a middle airbag, a right airbag, a fiber fabric net,a pull ring, a front crank, a rear crank, a front connection shaft, a rear connection shaft, a front rocking bar, a rear rocking bar, a sliding shaft and protective scales. The semi-soft robot is mainly composed of a left first airbag, a left second airbag, a left third airbag, a left fourth airbag, a middle first airbag, a right first airbag, a left first module, a left second module, a middle first module, a middle second module, a middle third module, a right first module, a right second module and a right third module. According to the semi-soft robot module and the semi-soft robot, the self-locking characteristic of a soft robot and the self-locking characteristic of a slider crank mechanism are combined, and thus, the semi-soft robot has the high stiffness after deformation and hasthe restoring force resistance, and through combination of the multiple modules, the semi-soft robot in multiple shapes can be formed; and stiffness change is completed automatically through a mechanical device, the stiffness is naturally improved after bending, the flexible state is recovered after straightening, and the control convenience is greatly improved.