The invention discloses a portable pocket-size washing machine. The portable pocket-size washing machine comprises an aluminum alloy cylinder. The two ends of the cylinder are provided with a front cover and a rear cover respectively. Two half-and-half buckled plastic base bodies are arranged inside the cylinder. A motor, a battery bin, a gear set and a high frequency telescoping mechanism which can be in clutch-type transmission connection with the gear set are embedded between the base bodies. The high frequency telescoping mechanism comprises a cylindrical telescoping guide base. A necking-down opening is arranged at the rear end of the telescoping guide base. A guide rod is inserted into the necking-down opening. The rear end of the guide rod is fixed into guiding grooves of the base bodies. The guide rod is sleeved with a spring. One end of the spring is fixedly connected with the fixing grooves. A liquid storage cylinder is arranged at the front end of the telescoping guide base. A pluggable cleaning head is arranged at the front end of the liquid storage cylinder. A fixing sleeve is sleeved with a body of the liquid storage cylinder in a slidable mode. Protruding guiding ribs and protruding blocks are arranged on the telescoping guide base. The end faces of the base bodies are provided with guiding grooves corresponding to the guiding ribs. Driving wheels matched with the protruding blocks are arranged on the gear set. The portable pocket-size washing machine is small in size, and the cleaning head can impact and clean dirty marks at high frequency.