Abstract Suspended ceiling (SC) systems constitute a critical nonstructural building component. Excessive deformation of the ceiling surface can cause life‐threatening falling debris during earthquakes and create voids that may expose occupants to hazardous materials concealed above the ceiling. To address limitations of the in‐service detection of SC deformation, this paper presents a point cloud–based full‐scene SC detection method, integrating region growing, Hough Transform, a customized Set2Seq network, and robust principal component analysis to achieve a complete workflow from ceiling segmentation, panel extraction to deformation quantification. Point cloud data with color information acquired from two precision‐differentiated devices are used in substage tests and holistic evaluation. The substage tests demonstrate that the local panel deformation quantitative accuracy of the proposed method is generally over 80%, and the holistic experiments show the feasibility of full‐scenario practical application.