Abstract: For low efficiency caused by manually putting dry concrete material into pug mill during underground guniting support, a new type of automatic loading and unloading device was proposed by analyzing structures of existing automatic loading and unloading devices, and structure design of the device was introduced in details. The device uses caterpilar belt running gear to move following pug mill, adopts closed clam bucket to reduce dust, and loads and unloads concrete material automatically, so as to improve supporting efficiency.