Conventional phase shifting shadow moiré profilometry usually needs more phase shifting images to demodulate the measurement phase because of the nonlinear phase shifting. The data sampling process is time-consuming and the measurement method is complex. We proposed a random three-frame object surface measurement method based on the principal component analysis and the shadow moiré profilometry. The phase shift is introduced by translating grating perpendicular to its own plane. Given that the background of captured fringe patterns is a smooth signal, we firstly normalized the sampled fringe patterns. Then principal component analysis based phase shifting algorithm is used to estimate the phase. The proposed method is fast and can be implemented easily in many applications. We also did optical experiments to demonstrate the effectiveness of the proposed method by referring to the result of conventional five-step phase shifting shadow moiré. The results show that the difference of the measurement results is within ±5 μm.