The embodiment of the invention discloses a memory control method and device for a terminal device, and the terminal device. The method comprises the steps of obtaining a memory occupation rate of branch applications corresponding to a master application in the terminal device; if the memory occupation rate of the branch applications is greater than a first preset threshold value, judging whether the branch applications satisfy a control condition or not; and if the branch applications satisfy the control condition, controlling processes corresponding to the branch applications. According to the scheme, after a user opens a plurality of applications, the fluent operation of a system still can be ensured, moreover, the operation time of the terminal device is prolonged, and system resources are saved.