To deals with the problem of estimating the relative pose between a camera and an object, this paper proposes a hybrid of vision and inclination sensor method for estimating relative pose.It is assumed that both the camera and the object are equipped with an inclination sensor, the resulting pose estimation problem can be seen as a PnP (perspective-n-point) problem with inclination constraint. First, this paper introduces the principle of the proposed method, simulations results certify that the proposed method can improve the computing accuracy and depress the image noise comparing with other solutions to the PnP problem. Finally, the experimental results show that the average reprojection errors of x and y directions for 15 feature points are less than 0.1 pixels by using the proposed method, which can meet the needs of pose measurement.