To enable an unmanned working machine to perform a proper working operation.In an unmanned lawn mowing system 1 including a plurality of unmanned lawn mowers 2 that perform lawn mowing work while being navigated in an unmanned manner； and a management server 6, each of the unmanned lawn mowers 2 communicating with the management server 6, each of the plurality of unmanned lawn mowers 2 includes: a travel control unit 42 that controls an operation based on a traveling parameter 51B； and a lawn mowing operation information collection unit 44 that collects lawn mowing operation information 54, the management server 6 includes: a lawn mowing operation information acquisition unit 60 that acquires the lawn mowing operation information 54 from each of the unmanned lawn mowers 2； and an optimal setting specifying unit 64 that specifies, for each of the unmanned lawn mowers 2, a value of the traveling parameter 51B suitable for the lawn mowing work based on the lawn mowing operation information 54, and each of the unmanned lawn mowers 2 controls an operation based on the value of the traveling parameter 51B specified by the management server 6.
