Surface soil moisture estimates (SSM) from microwave sensors onboard the polar-orbit satellites are important data sources for investigating hydrological signatures of the global terrestrial area. However, daily SSM products from any single satellite platform have significant inter-swath gaps and thus incomplete spatial coverage in low latitudes. This can lead to a longer revisit cycle (2–3 days) than on a stable daily revisit for the data products in tropical and subtropical zones, especially for the state-of-art L-band passive microwave SSM products, e.g. SMAP or SMOS. Meanwhile, data blending techniques based on combination of different SSM products have the potential for overcoming this problem. But difficulties can exist on dealing with the inconsistency of error characteristics between different satellite data sources. Moreover, although some blended SSM products have been well recognized (e.g. ESA CCI or SMOPS), they do not discriminate the possibly inconsistent overpass local time of different participating sensors, making the blended estimates less capable to capture sub-daily variations of soil moisture. The recently developed active microwave sensor of FY-3E Wind Radar (WindRAD) shares similar overpass local time with SMAP in the dawn-dusk orbit, and thus provides the great possibility for SSM blending between the two sensors. To realize this purpose, we developed an algorithm in this study for retrieving SSM using FY-3E WindRAD backscattering signals as the primary data input. The algorithm is originated from the conventional Water-Cloud model, while the model constants were fitted on each pixel against SMAP SSM estimates. We used ground soil moisture measurements from >400 stations over the globe to evaluate the relative performances among SSM retrievals from FY-3E WindRAD, SMAP, and another well-known active microwave sensor, i.e. ASCAT. Results show that for most ground stations under low-to-moderate vegetation conditions, our developed FY-3E WindRAD SSM product obtains an overall evaluation accuracy that is very close to the SMAP SSM product (ubRMSD values principally between 0.02 and 0.06 cm3/cm3) and is apparently higher than the conventional ASCAT SSM (ubRMSD values principally between 0.03 and 0.10 cm3/cm3). The results also show that combination between our developed FY-3E WindRAD SSM and SMAP SSM can well increase the effective daily global coverage of the single FY-3E product or even the SMOS-SMAP blended product from 40%–50% to around 70% in low latitudes. Our study reveals the perfect potential of FY-3E WindRAD in producing synchronous SSM observations that are spatially complementary to the widely recognized SMAP product in the dawn-dusk orbit. It also provides new insights on filling low-latitudinal gaps existing in most polar-orbit satellite microwave data.