Metasurfaces have intrigued great interest among researchers in electromagnetic (EM) engineering field due to the powerful ability of EM manipulation and advantages of low loss, low profile and ease-fabrication. Nevertheless, due to the limitation of the fabrication technology, currently, most of the reported metasurface carpet invisibility cloaks are composed of two-dimensional planar structures. It is still a challenge to achieve conformal metasurface carpet invisibility cloak for an object with arbitrary boundary. Therefore, we designed and demonstrated a conformal metasurface carpet invisibility cloak with arbitrary boundary based on metasurfaces and 3D-printed technology, which breaks the limitation of two-dimensional planar structures and achieves radar stealth for ground object. Both simulated and measured results show that such conformal metasurface invisibility cloak exhibits an excellent stealth performance and sustains performance stability at certain incident angles. Notably, the proposed 3D conformal metasurface invisibility cloak not only promises a wide application prospect in the EM stealth field, but also opens a new way to design EM devices.