We design and implement a compact 85Rb atom gravimeter (AG). The diameter of the sensor head is 35 cm and the height is 65 cm; the optical and electronic systems are installed in four standard 3U cabinets. The measurement accuracy of this AG is improved by suppress laser crosstalk and light shift. In addition, the angle of the Raman laser reflector is adjusted and locked, and the attitude of the sensing head is automatically adjusted, and the vibration noise is also compensated. The comparison measurement results between this AG and the superconducting gravimeter indicate that its long-term stability is 0.65 μGal @50000 s.