A fidelity retaining type coring device for a rock sample, comprising a rock core drilling tool, a rock core sample storage barrel, and a rock core sample fidelity retaining cabin. The rock core drilling tool comprises a coring drilling tool, a core catcher (11), and an inner core pipe (12); the coring drilling tool comprises an outer core pipe (13) and a hollow drill bit (14), and the drill bit (14) is connected to the lower end of the outer core pipe (13); the lower end of the inner core pipe (12) extends to the bottom of the outer core pipe (13), and the inner core pipe (12) is in clearance fit with the outer core pipe (13); the rock core sample fidelity retaining cabin comprises an inner coring barrel (28), an outer coring barrel (26), and an energy accumulator (229); the outer coring barrel (26) is sleeved on the inner coring barrel (28); the upper end of the inner coring barrel (28) is communicated with a liquid nitrogen storage tank (225), and the liquid nitrogen storage tank (225) is located in the outer coring barrel (26); the energy accumulator (229) is communicated with the outer coring barrel (26); the outer coring barrel (26) is provided with a flap valve (23). According to the device, a rock core can maintain its state in an in-situ environment; in addition, the drilling speed can be increased, and the coring efficiency can be improved.