The invention relates to an improved hybrid ring-based multi-frequency rectifier circuit, which comprises an input connector, an improved hybrid ring, a low-frequency branch, a middle-frequency branchand a high-frequency branch, wherein the input connector is connected with an input end of the improved hybrid ring; the low-frequency branch comprises a low-frequency impedance matching network, a low-frequency voltage-doubling rectifier branch and a low-frequency harmonic suppression branch; the middle-frequency branch comprises a middle-frequency impedance matching network, a middle-frequencyvoltage-doubling rectifier branch and a middle-frequency harmonic suppression branch; and the high-frequency branch comprises a high-frequency impedance matching network, a high-frequency voltage-doubling rectifier branch and a high-frequency harmonic suppression branch. Three output ends of the improved hybrid ring are connected with the low-frequency branch, the middle-frequency branch and the high-frequency branch separately; and the improved hybrid ring has matching and shunting functions.