The improper operation，fatigue operation and position judgment deviation during the operation of bucket wheel stacker reclaimer often cause stack collapse during the reclaiming operation. The collapse will occur in the safety accident such as serious overload and even equipment overturning when the bucket wheel is partially or completely buried. We adopt 3D laser scanner to scan the surface of the stack，carry out the real-time point cloud data processing and online three-dimensional reconstruction，analyze and recognize the shape of the real-time working surface of the stack. By calculating the position relationship between the current reclaiming surface and the upper working surface，the technology can automatically judge whether there is a risk of collapse and whether the full-automatic reclaiming operation can be continued. The results show that the proposed anti-collapse technology can well prevent the stack collapse in the reclaiming process.