According to the feature of the passive carrier-envelope phase (CEP) stabilized idler of the optical parametric amplified process, a CEP stabilized three-stage collinear optical parametric amplifier is built. Millijoule ultrashort infrared output (1.4 mJ/40 fs/1 kHz at 1.8 μm) with CEP fluctuation ~516mrad is obtained from the system. After passing through a hollow-core fiber and block material, the pulses are finally compressed to less than two cycles (<12 fs), and the single pulse energy is 0.54mJ. The system provides an excellent laser source for the experiments of individual attosecond pulse generation and other high harmonic generation (HHG).