A Wilkinson power divider (PD), which can suppress the second, third, and fourth harmonics is proposed. The PD is implemented based on an asymmetric meta-structure. The meta-structure is constructed be combing defect ground structure (DGS) and spoof surface plasmon polariton (SSPP). It can not only realize the impedance conversion function in the operating frequency band, but also realize the suppression of the second, third, and fourth harmonics. The simulation and measurement results show that this structure can achieve −32 dB suppression for the second harmonic, −31 dB suppression for the third harmonic, and −28 dB suppression for the fourth harmonic respectively.