A novel dual-heated water and power cogeneration system (WPCS), in which photovoltaic/thermal (PV/T) is used for seawater heating and electricity generation, and solar collector is applied for air heating, based on the humidification-dehumidification (HDH) cycle, is proposed. Comprehensive performance of the dual-heated WPCS is obtained, and the parametric analysis, from the pinch enthalpy difference (PED) within the humidifier and solar intensity, are accomplished. It is found the peak gained-output-ratio (GOR), water production and water production cost (WPC) 2.55, 76.32 kg & BULL;h-1 and 15.14 $t-1, with an uneconomical payback period (PBP). The parametric analysis implies a lower PED and higher solar intensity are profitable to raise the water production, while the GOR will decrease instead when the solar intensity rises. Furthermore, it is illustrated a higher PED and solar intensity can reduce the PBP. It is concluded the combined applications of the PV/T and solar collector can result in the advantages, to neutralize the features of the single heated, wateror air-heated HDH systems, HDH desalination methods for raising water production and GOR. However, the impossibility to recover the cost of the dual-heated WPCS within the working lifetime is also discovered, although this is of less importance in areas with water shortages.