Industrial Safety accidents occur on construction site all the time, yet failure to wear hard hats properly accounts for a large percentage of significant injuries and deaths. It is difficult for managers to control each worker's condition because it is too complex. To solve the problem, installing detectors on hard hats and connect to the app. Managers can manage workers via the app. DLT also enhances the willingness to wear hard hats by Improving the problem of traditional hard hats. When accidents occur, the DLT app will notice managers and provides the first aid information of injuried workers to protect workers' life safety.