The present invention provides a kind of permanent magnetic lifting device, which has: a housing, at the bottom of which is a clamping surface for clamping objects; fixed magnet(s), set in housing relatively fixed to housing; a turnable magnet, set in housing relatively turnable to fixed magnet. When turnable magnet is in the first position relative to fixed magnet, the magnetic force generated by fixed magnet and turnable magnet to clamping surface is zero magnetic force; when turnable magnet is in the third position relative to fixed magnet, the magnetic force generated by fixed magnet and turnable magnet to clamping surface is the maximum magnetic force. The permanent magnetic lifting device also has a positioning mechanism for second position. When the positioning mechanism for second position positions turnable magnet in the second position relative to fixed magnet, fixed magnet and turnable magnet generate trial clamping magnetic force to clamping surface for clamping objects on trial. The trial clamping magnetic force is higher than zero magnetic force and lower than maximum magnetic force. The permanent magnetic lifting device enables an operator to easily operate trial clamping, and also to know whether the ratio of the maximum clamping force that can be generated by the permanent magnetic lifting device under the specific condition to the weight of the workpiece equals or exceeds 2 times or 3 times or other specific values, and through operation of trial clamping, potential risk in safety can be thoroughly eliminated.