The invention provides a drum type automatic screen printing machine, comprising a conveying unit, a printing unit and a paper delivering unit; the printing unit comprises a rack, as well as a screen frame, a screen bracket, a drum and a printing head arranged on the rack; the rear support plate of the screen bracket is provided with a screen adjusting and locking device; a screen tightening device is arranged at each of the four corners of the screen bracket; the printing head comprises a scraper, a scraper holder, a scraper head box, a scraper pressurizer, a scraper angle adjusting and locking device, a scraper position adjusting device and a scraper changing device. The screen bracket of the drum type automatic screen printing machine is of a ramp type, so that the screen cloth can be washed just by aslant uplifting the screen bracket with hands as the screen bracket is supported by an air spring, and thus the screen cloth is simpler and more convenient to wash. Meanwhile, in the drum type automatic screen printing machine, a sealed oil line is composed of a reducing valve, an oil storage seat, an oil cylinder, an oil valve seat and the like, and a control gas circuit consisting of an external gas source and the reducing valve is used for controlling the scraper holder, so that the stability of the scraper holder is greatly improved.