Low power density and high cost are the key factors that prevent the solid-state transformer (SST) from further application in the distribution network. Therefore, a novel power integrated modular multilevel solid-state transformer(PI-MMSST) is proposed, aiming at reducing the device volume and increasing the overall power density through power integrating the input stage and intermediate stage of the conventional three-stage SST. Furthermore, as compared to the recently proposed mixed-modulation SST topologies, the PI-MMSST reduces the use of filters and saves the cost of whole system with the help of the new power distribution concept. Based on the common carrier modulation, the working principle of the topology is analyzed, and a dual-layer control strategy is proposed to achieve the voltage balance of the submodule capacitors. Simulation results from Matlab/Simulink validate the feasibility and effectiveness of the PI-MMSST topology and dual-layer control strategy.