The invention relates to a bridgeless forward power factor correction device. When the traditional power factor correction circuit operates, the number of semiconductor power devices turned on simultaneously is larger, and the power loss is higher. The bridgeless forward power factor correction device comprises a power main circuit and a control circuit. The main circuit mainly comprises an input side circuit, a transformer T and an output side circuit. The control circuit comprises an output voltage or output current feedback circuit, an alternating current input voltage phase detection circuit, a magnetic reset detection circuit of the transformer T, a PFC (Power Factor Correction) controller and a driving circuit. Compared with the traditional BoostPFC circuit, a single-level circuit can satisfy low-voltage applications, and the requirements on front and back level isolation of the circuit can be met.