One of the main problem of modern micro - and nanoelectronics is the searching for new materials for creation of new generation of multifunctional electronic components, as well as a comprehensive study of the functional and structural properties of these materials.  Various magnetic materials and structures are traditional objects of research in this area. The fastest way to switch magnetic moment is the impact of ultrafast electromagnetic pulses, for example, femtosecond laser pulses. Ferroelectric materials are an alternative of magnetic materials to create nonvolatile memory. For example, the optical polarization switching can be realized in ferroelectric-semiconductors due to the influence of the electron subsystem on the ferroelectric and electrical characteristics.    The material Sn2P2S6 was chosen to investigate this possibility, because it is a ferroelectric- semiconductor by nature, and the potential of its use as electronic components is higher than that of ordinary ferroelectrics.  For a new generation of electronic devices high-speed processing and storage of information the possibility of optical control using femtosecond laser pulses of the polarization state of coherent quantum control of phonons is expected.  In this work we present the experimental study results of the nonlinear optical response temperature dependence in ferroelectric-semiconductor Sn2P2S6 (SPS) near the phase transition temperature. The dynamics of the nonlinear optical response relaxation in Sn2P2S6 crystal was studied by the time-resolution spectroscopy technique in the picosecond time range. In this experiment, the crystal temperature was passing through the phase transition temperature.  The  absence of Curie temperature effective change in the crystal under the femtosecond laser radiation action was shown, as well as the low threshold of material destruction were made.  This work is supported by Russian Ministry of Science and Education (contract № 14.Z50.31.0034).