Abstract: The direct steam generation in parabolic trough collectors systems（DSG-PTC） with different capacities and working-medium flow path were designed. The integration schemes for the integrated solar combined cycle system（ISCCS） taking DSG-PTC as the auxiliary heat source were put forward. The real-time dynamic simulation models for the ISCCS were studied based on the previous research achievements. With these dynamic simulation models, the operating characteristics of ISCCS were analyzed, the matching principle of the working-medium flow and energy flow between two energy systems were indicated, the control strategy improving suggestions in ISCCS are put forward, the dynamic response characteristics of the ISCCS are researched, the thermal economy of the ISCCS in different integration schemes are calculated, and the optimal integration scheme is proposed.