Disclosed is a vehicle seat sliding device, which prevents noise from being generated when a seat is moved. The vehicle seat sliding device includes: a fixed rail which includes a locking section in which a fixed lock is formed and an unlocking section in which the fixed lock is not formed; a moving rail which slides along the fixed rail; a locking unit which is provided in the moving rail, moves up and down, and has a plurality of locks that is selectively engaged with the fixed lock. When at least one lock of the plurality of locks is located in the unlocking section, remaining locks located in the locking section are disposed apart from the fixed lock so as to have a gap with the fixed lock. With this configuration, when the moving rail is returned from the unlocking section to the locking section, the lock of the locking unit is disposed apart from the fixed lock provided in the fixed rail in such a way as to have a gap, so that noise can be prevented from being generated.