A memory startup method of a computer, comprising: initializing, by a basic input/output system of the computer, only a first part of memory of the computer in a memory initialization phase when the computer is powered on and started, wherein the first part of the memory is a preset memory part of the memory of the computer, and the first part of the memory that is initialized can satisfy a memory requirement for startup of an operating system that runs in the computer; and continuing to initialize, by the basic input/output system, memory, except the first part of the memory, of the memory of the computer after the operating system of the computer is started, and notifying the operating system of the computer of the initialized memory except the first part of the memory, so that the operating system of the computer further initializes the memory, except the first part of the memory, of the memory of the computer, and adds the memory that is further initialized to available memory of the operating system; wherein the further initializing, by the operating system, the memory, except the first part of the memory, initialized by the basic input/output system comprises: determining, by the operating system, whether the memory that is further initialized satisfies a memory size required by a to-be-started process, and when a size of the memory that is further initialized does not satisfy the memory size required by the to-be-started process, waiting for a preset time; and when the size of the memory that is further initialized satisfies a requirement of the to-be-started process, starting, by the operating system, the to-be-started process, and when the size of the memory that is further initialized satisfies memory required by startup of two or more processes, starting a process with a higher priority. initializing, by a basic input/output system of the computer, only a first part of memory of the computer in a memory initialization phase when the computer is powered on and started, wherein the first part of the memory is a preset memory part of the memory of the computer, and the first part of the memory that is initialized can satisfy a memory requirement for startup of an operating system that runs in the computer; and continuing to initialize, by the basic input/output system, memory, except the first part of the memory, of the memory of the computer after the operating system of the computer is started, and notifying the operating system of the computer of the initialized memory except the first part of the memory, so that the operating system of the computer further initializes the memory, except the first part of the memory, of the memory of the computer, and adds the memory that is further initialized to available memory of the operating system; wherein the further initializing, by the operating system, the memory, except the first part of the memory, initialized by the basic input/output system comprises: determining, by the operating system, whether the memory that is further initialized satisfies a memory size required by a to-be-started process, and when a size of the memory that is further initialized does not satisfy the memory size required by the to-be-started process, waiting for a preset time; and when the size of the memory that is further initialized satisfies a requirement of the to-be-started process, starting, by the operating system, the to-be-started process, and when the size of the memory that is further initialized satisfies memory required by startup of two or more processes, starting a process with a higher priority. determining, by the operating system, whether the memory that is further initialized satisfies a memory size required by a to-be-started process, and when a size of the memory that is further initialized does not satisfy the memory size required by the to-be-started process, waiting for a preset time; and when the size of the memory that is further initialized satisfies a requirement of the to-be-started process, starting, by the operating system, the to-be-started process, and when the size of the memory that is further initialized satisfies memory required by startup of two or more processes, starting a process with a higher priority.