High pressure gaseous Time Projection Chamber (TPC) with Micromegas, which is considered to be a very attractive solution for the next generation of ton scale 0vββ experiment, features the high granularity, high energy resolution, and low radioactive background. The PandaX-III experiment adopted the TPC scheme and will search for 0vββ of Xe-136 at China Jinping Underground Laboratory. In this work, we present R&D of Micromegas with thermal bonding method at USTC. Thermal bonding Micromegas offers spark-resistant and dead-channel-free readout modules for readout. We first report the specific design and manufacturing process for this radio-pure and high energy resolution Micromegas detector with active area of 200mm×200mm. The prototypes were characterized under 10 bar pressure and the performance such as gas gain, energy resolution, and long-term stability etc, were studied in detail, and the results are presented and show a promising solution for PandaX-III experiment.