As a type of multi-field coupled materials, piezoelectric semiconductors have a strong dependency on temperature. Nanostructures have large surface-volume ratio and different mechanical and electrical behaviors from structures at the macroscopic scale, i.e., there exists a scale dependence. In this paper, based on the first-order shear deformation theory, a two-dimensional simplified piezoelectric semiconductor nanoplate model with thermoelectric effect and surface effect is developed. Dynamic bending behaviors of the nanoplate under the mechanical load and thermal flux are studied. The nonlinear terms among the temperature, electric field, and electron concentration in the heat flux density constitutive equation are induced by the thermoelectric effect. A direct iterative method is adopted with the finite element method to analyze the dynamic bending behaviors. Then, the thermal, mechanical, and electrical dynamic responses are numerically obtained. Different thermal effects on the distributions of the temperature and electromechanical fields in the piezoelectric semiconductor nanoplate are discussed, and the conversion mechanism of the mechanical energy, electrical energy, and heat is revealed.