Constructing the highly efficient and stable quasi-solid-state even solid-state devices is one of the most significant tendency in the field of quantum dots sensitized solar cells (QDSCs). Herein, highly efficient and stable quasi solid-state (QS)-QDSCs devices were fabricated via synergistically combining the TiO2-sol interconnecting modified photoanodes with alginate hydrogel (AH)-assisted electrolyte films. TiO2-sol binding agent could incorporate into the surface and voids of TiO2 particles, which increased the surface area and roughness for QDs loading and induced better connection between the neighboring particles. Meanwhile, the AH-assisted QS electrolyte films possessed the crosslinking hydrogel network structure and exhibited the perfect interfacial contact with the modified TiO2 surface, thus enhancing the ion transport and redox reaction of polysulfide couple. Benefited from the synergistic effect of TiO2-sol modified photoanodes and alginate hydrogel (AH)assisted electrolytes, a champion power conversion efficiency (PCE) of 8.87% for model ZnCuInSe (ZCISe) based QS-QDSCs was achieved with an enhancement of near 10% related to that of the devices based the pristine devices (8.01%), and very close to that of liquid-junction QDSCs (9.06%). Moreover, the constructed QS-QDSCs devices exhibit the excellent stability. This work thus provides a facile and effective strategy to achieve the QSQDSCs devices with both of high efficiency and good stability.