This paper presents THU-SOC, a new methodology and tool dedicated to explore design space by executing full-scale SW application code on the transaction level models of the SoC platform. The SoC platform supports alternative Transaction Level Models (TLMs), bus-functional model and bus-arbitration model, which enables it to cooperate with different levels of hardware descriptions. So, users are only required to provide functional descriptions to construct a whole cycle-accurate system simulation for a broad design space exploration in the architecture design. When the architecture is determined, the high-level descriptions can be replaced by RTL-level descriptions to accomplish the system verification, and the interface between the tool and the descriptions is unmodified. Moreover, THU-SOC integrates some behavior models of necessary components in a SoC system, such as ISS (Instruction-Set Simulator) simulator of CPU, interrupt controller, bus arbiter, memory controller, UART controller, so users can focus themselves on the design of the target component. The tool is written in C++ and supports the PLI (Programming Language Interface), therefore its performance is satisfying and different kinds of hardware description languages, such as System-C, Verilog, VHDL and so on, are supported.