Graphene has the features of high electron mobility, high transmittance (T≈97.7%) and adjustable Fermi energy. The electron mobility of GaAs is 5 to 6 times higher than that of silicon. After introducing indium arsenide quantum dots, the photoelectric detector will has the features of low dark current, high operation temperature, high responsivity and high detectivity. Therefore, it can be used to fabricate fast, high quantum efficiency and wide spectrum photoelectric detectors. The I-V characteristics and photoresponse of a Schottky junction based on a graphene-InAs/GaAs quantum dot hybrid structure are studied. The results show that at the bias voltage of 0 V, the device shows its photoresponse in the wavelength range 400 nm to 950 nm with the peak response of 0.18 A/W. At the reverse bias voltage, its peak response can reach 0.45 A/W. Through the analysis of the temperature dependence of dark current, the barrier height of the Schottky junction at room temperature and 80 K is obtained.