Based on the solubility experiments of acid-rock reaction, using ICP、19FNMR、31PNMR、XRF and XRD analytical technique to analyze the ions concentration and chemicals in spent acid and reaction-after residues so as to research reaction performance between multi-hydro acid and sandstone minerals and to evaluate the deep-penetration effect of multi-hydro acid by core flooding experiments under high temperature and high pressure. The ICP and XRD results showed with the increasing of temperature, the possibility of producing silica gel will increase, and when the temperature is up to 150℃, all the reaction between acid and 4 sorts of minerals will generate silica gel precipitation. XRF and XRD results demonstrated that 6% multi-hydro acid has a stronger solubility to sandstone minerals; and the reaction between multi-hydro acid and kaolinite, bentonite or illite can’t generate AlF3 secondary precipitation, but when reacts with chlorite, AlF3 precipitation could generate. And NMR results showed the same situation as well as multi-hydro acid has a good performance to chelate metal ions. Core flooding experiment demonstrated multi-hydro acid increased formation permeability by 53.3%, on the contrary conventional mud decreased by 28%;the result from measuring effluent of core flooding tests by ICP confirmed that multi-hydro acid chelated metal ions, and conventional mud acid formed silica gel.