In order to meet the requirements of uploading and downloading large-capacity data in all-optical networks, a reconfigurable optical add-drop multiplexer (ROADM) based on wavelength division multiplexing (WDM), polarization division multiplexing (PDM) and space division multiplexing (SDM) is proposed, which can improve the uploading and downloading capacity of optical add-drop multiplexer (OADM) by 12 times. The OADM system based on WDM and PDM is built experimentally and performances are analyzed. Results show that the OADM based on WDM and PDM can achieve dense WDM and realize PDM steadily. The stability of the polarization state at main output port achieves 0.01, the splitting ratio of fast and slow axes at polarization beam splitter output port is close to 1∶1, and the insertion loss is lower than 9 dBm. The OADM models based on photonic lantern (PL) and SDM are established, and the multimode multiplexing of six-mode and three-mode are realized respectively. Results show that the effective refractive index difference between different modes of OADM based on PL and SDM is larger than 6×10-4, which indicates low inter mode interference and high isolation degree.