The experimental method of non-contact vibration measurement is applied to investigate the parametric resonance of a clamped-clamped pipe conveying fluid. A laser vibration measurement is used to obtain vibration information of the middle part of the pipe excited by a pulsating flow. It is very important to find out the corresponding exciting frequency when the 1/2 frequency appears and disappears in the spectrum graph of pipe vibration. Then, based on the results of many experiments, the regions of the 1/2 sub-harmonic parametric resonance of the first mode shape are fitted, which are qualitatively consistent with the theoretical results calculated by the averaging method. The conclusions obtained show that at a certain flow velocity, the phenomena of parametric resonance can occur with the proper pulsating amplitude and frequency, and the position of parametric resonance regions are closely related to flow velocity. It is also concluded that the actual region of the parametric resonance is larger than the theoretical one, which may be relevant to the results calculated by the method of averaging. In addition, some analysis on experimental errors is given.