In order to further improve the sensitivity and stability of aluminum-based plasmonic sensor, a plasmonic configuration named aluminum-graphene hybrid structure, was proposed based on phase modulation. Employing a high refractive index prism, the plasmonic configuration excited by the Kretschamnn mode, was designed by depositing graphene layers onto aluminum film. With the help of the transmission matrix theory, the variation of geometry parameters on sensing performance was studied when the excitation wavelength With the help of the transmission matrix theory, the variation of geometry parameters on sensing performance was studied when the excitation wavelength was set to 632.8 nm. The calculated results show that, the proposed aluminum-graphene hybrid structure designed by phase modulation have provided 2 orders of magnitude higher sensitivity compared with conventional surface plasmon resonance sensors designed by angular modulation. Moreover, the introduction of graphene can not only efficiently hinder the oxidation of plasmonic aluminum film, but also enhance the detection sensitivity as high as 83 times. For a tiny refractive index variation of 1.333~1.334 2 in sensing interface, the proposed configuration can provide a higher phase change of 94.663° and a phase detection sensitivity as high as 7.888 5×10^{4 o}/RIU. The proposed surface plasmon resonance configuration can provide a reference for designing low-cost and ultrasensitive plasmonic sensors.