The invention provides an HCCI micro free piston electric generator. The HCCI micro free piston electric generator comprises a stator and micro free piston power devices. The stator is provided with amain air inlet, the stator is divided into stator work units through the main air inlet, the stator work units are symmetrically distributed and are of the same structure, fixed dividing rings are arranged in the stator work units, the micro free piston power devices are arranged in the stator work units, a work chamber comprises a combustion chamber and a pressure chamber, the pressure chamber is communicated with the main air inlet, a combustion chamber air inlet and a combustion chamber exhaust opening are formed in the combustion chamber, a pressure chamber air inlet is formed in the pressure chamber, the pressure chamber air inlet and the combustion chamber air inlet are connected through a pipeline, a one-way valve is arranged on the main air inlet, and an exciting winding and a stator winding are arranged on the inner wall of each stator work unit. Mechanical energy is directly converted into electric energy, waste gas waste heat is used for preheating mixed gas, the initial temperature of the mixed gas is improved, and compression combustion of the mixed gas is facilitated.