The invention discloses a plasma assisted epitaxial growth device and method. The device comprises a vacuum reaction chamber, a sample stage, a plasma excitation unit, a first air inlet, a second air inlet and an airflow regulation and ion control device, wherein the plasma excitation unit is positioned on the top of the vacuum reaction chamber; the first air inlet is used for introducing a first gas-state reaction source into the vacuum reaction chamber; the second air inlet is used for introducing a second gas-state reaction source into the vacuum reaction chamber; the airflow regulation and ion control device is positioned between the first air inlet and the sample stage and comprises a first gas channel group and a second gas channel group isolated from each other; the first gas channel group is used for controlling a flow field of the first gas-state reaction source; the second gas channel group is used for controlling a flow field of the second gas-state reaction source; the plasma excitation unit is used for exciting ionization and decomposition of the first gas-state reaction source; the sample stage can heat the second gas-state reaction source to be subjected to thermal cracking. The plasma assisted epitaxial growth device and method in the embodiment of the invention has the advantages that the device is low in growth temperature and suitable for growth of multiple nitride semiconductors.