A 3D flame projection system is provided, comprising a light source and a light-transmittable hood. The light source is disposed inside the light-transmittable hood. The 3D flame projection system further comprises a lens which has different refractive indexes for refracting light generated by the light source and splitting the light into a plurality of light beams at different angles and/or has different light transmittances for allowing light generated by the light source to partially transmit through the lens. The 3D flame projection system has the following advantages: simple structure, low cost, small space occupation, realistic flame dancing effect, and it is advantageous for realization of ultrathin production of fireplaces.