A detachable handheld laser scanner system supporting multiple plug-in combinations, including a main unit, an extension member and multiple external components. A housing of the main unit is provided with the extension member. The extension member includes an engagement cavity recessed on a side of the housing, a data interface provided on an inner wall of the engagement cavity and a clamping part movably provided in the housing. The engagement cavity has a first side wall and a second side wall oppositely provided in a second direction intersecting the first direction. The external components include a lidar module, a structured-light scanning module, an image acquisition module or a combination thereof. Each external component is provided with an engagement portion configured to engage with the engagement cavity. A surface of the engagement portion is provided with a data connector mating with the data interface.