Computer system, mixing memory and method for controlling power supply of computer memory

The invention provides a computer system, a mixing memory and a method for controlling a power supply of a computer memory. The computer system comprises at least one part of operation system, a second memory and a first control module, wherein the at least one part of operation system is installed in a computer and at least can perform a first function independently; the second memory is physically independent of a first memory and is used for storing data; the first control module is used for controlling the power off of the second memory when the computer performs the first function and a first condition is met; and the first condition is a condition under which the second memory needs power off. Through the scheme, the power consumption of the computer memory is lowered and the service time of a computer battery is prolonged.