A construction machine control system includes: a target construction ground shape generation unit which generates a target construction ground shape indicating a target shape of an excavation target; a working device control instruction determination unit which outputs an instruction for driving the working device in a working device operation plane orthogonal to at least one of a boom axis, an arm axis, and a bucket axis based on an operation state of at least one of an arm and a bucket and a distance between the bucket and the target construction ground shape; and a tilting control instruction determination unit which outputs an instruction for performing a tilting control of the bucket about a tilting axis based on a tilting state of the bucket and the distance between the bucket and the target construction ground shape.