The kinematic modeling and extrinsic parameter calibration problems of the ceiling projector in the service robot intelligent space (SRIS) are investigated. Firstly, the D-H method is used to set up the kinematic model of the projector. Then, according to solving a set of equations of the rotation matrix using a novel nonlinear iterative optimization algorithm, the extrinsic parameter of the projector is calibrated. Finally, some experiments are designed to verify the kinematic model’s correctness and the calibration algorithm’s accuracy. The experimental results show that, the modeled and calibrated projector can project the laser spot moving along a desired path on the ground, with which the navigation tasks for the low-cost service robot can be accomplished efficiently and accurately.