Taking rape straw and anthracite and bituminous coal as the research object, based on the simultaneous thermogravimetric technology, the dynamic characteristics of cocombustion were studied systematically with different mass fractions of wheat straw (100%, 60%, 40%, 20%, 10% and 0) and the ratio was optimized. The results showed that WS was rich in volatile matter with a content of 75.69%, while bituminous coal had the highest fixed carbon content (54.77%). Therefore, the fuel ratio (fixed carbon/volatile) of BTC (167) was much larger than that of WS (014), indicating that bituminous coal was more conducive to combustion. There was significant difference on cocombustion characteristics under different mass fractions from TG and DTG curves. From DTG curves of cocombustion, it can be seen that as the proportion of wheat straw was decreased, the volatile combustion peak was gradually decreased from 2079%/min to 208%/min (WS10%). The maximum rate of fixed carbon combustion of wheat straw (4033%/min) appeared at 419℃. The ignition temperature was not significantly improved when the ratio of straw was declined to 10%, which was within 260~268℃, indicating a desirable performance of ignition. While the burn out temperature was significantly improved along with the decrease of straw from 520℃ (WS) to 596℃ (BTC). The comprehensive index (SN) value was decreased from 8.78×10-7%2/(K3·min2) to 1.17×10-7%2/(K3·min2) as the straw ratio was decreased, indicating that the combustion performance was gradually weakened. However, the group WS40% with a SN value of 3.60×10-7%2/(K3·min2) can ensure better combustion behavior. From DSC analysis, mixture with 40% propotion of WS can release heat up to 84.14% of BTC’s.In summary, based on the evaluation of combustion performance and improving heating value of mixture, the mass fraction of 40% was recommended for wheat straw when blended with bituminous coal for cocombustion.