A joint imaging by teleseismic converted and multiple phases is put forward to image the crustal structure beneath the INDEPTH-III passive seismic profile in the central Tibet. A depth dependent Vp/Vs ratio is adopted to map common conversion point (CCP) via a Vp/Vs scanning and stacking approach. Our new crustal image shows that the crust is divided into two sections with different Moho depth distributions and amplitudes, with the boundary nearby the Bangong-Nujiang suture (BNS). A negative P-to-S amplitude band is located in the upper-to-middle crust, indicating a low velocity zone possibly caused by partial melting beneath the negative amplitude band. The average crustal Vp/Vs ratio estimated by our joint imaging method is higher than previous study, but is consistent with a partial melting middle-to-lower crust implied by many other results.