Abstract: A book copying machine comprises a housing covered with a movable exposure glass at the top and having set therein a microprocessor, a copying camera system, a carbon powder feeding and image setting device, a paper turn-over device and a return delivery device. The movable exposure glass comprises a transverse wedge portion in the middle which can be driven to displace by a driving device so as to fit the surface curvature of the fold of a book. Through the control of the microprocessor to coordinate the parts of the machine, page editing is simply achieved by piling up the duplicated sheets of paper which are folded up respectively.