Based on the theory of photoacoustic (PTA) effect of solids, a theoretical model of PTA effect for multilayered graphene film was established, and the sound pressure expression of the PTA signal from a multilayered graphene film was derived. After performing theoretical calculations and experimental tests on PTA effect of the graphene films of different substrates under ultrafast pulsed lasers, it shows that theoretical values basically coincide with test results in the frequency domain, which effectively validates the theoretical model. Furthermore, the sensitivity analysis method was used to analyze the relevant factors that affect the photoacoustic efficiency of the graphene film. The analysis indicates that the thickness (5-15 nm) of graphene lms plays a trivial role in efciency, and the sensitivity coefcient is less than 0.01. The substrate thermal effusively has signicant effects on efciency, with the sensitivity coefcient around 1.88; substrates with lower thermal effusivity exhibit better acoustic performances. The sensitivity coefficients of ambient gas density, thermal conductivity and specific heat are 1.09, 0.97, and 0.9, respectively. The sound pressure level generated by graphene films is approximately proportional to the inverse of specific heat. This research is of instructive importance to the application of graphene films in PTA loudspeakers and other related fields.