A pipe support device includes a main body to support a pipe thereon and a pair of stoppers provided on the main body to position the pipe on the main body. The pipe support device is provided in an excavated trench to support the pipe in the trench. The main body and the pair of stoppers each have an internal space into which a fluid is injectable and from which the fluid is dischargeable, and are configured to expand by injection of the fluid into the internal space and to contract by discharge of the fluid from the internal space.