A thermal printer comprises a base part, a platen roller and a thermal head oppositely arranged, a pickup roller, and a gear set connecting the platen roller and the pickup roller. The base part is provided with a printing paper accommodating cavity and a pickup roller mounting frame, a plurality of printing paper sheets are disposed in the printing paper accommodating cavity, and a clutch mechanism is further provided. The clutch mechanism comprises a driving portion driven by the gear set and a driven portion for driving the pickup roller to rotate. The driving portion is disposed outside the pickup roller mounting frame, such that the impact force, which is generated by the remaining printing paper sheet that falls down when the printing paper sheet departs from the pickup roller and which is transmitted to the platen roller, can be reduced. The thermal printer is capable of providing smooth printing.