As a market and policy innovation,China's national carbon market attracts great attention at home and abroad. In order to ensure its smooth establishment and sustainable development,it is rather urgent to learn from relevant best practices. However,as the only references in China,the 7 pilot carbon trading schemes could only provide very limited experiences. Therefore,studying and learning from EU-ETS - the largest carbon market in the world has become very important. As a significant indicator of whether a market matures or not,carbon price is able to present considerable signal. Various scholars have found respectively that prices of CER carbon,crude oil,coal and natural gas,along with Euro Stoxx index,UN climate change conferences,government policies,extreme weathers,warm winters,natural disasters and important events can all trigger EUA carbon prices fluctuating. This study therefore tries to introduce a MIV-BP model to train and test EUA prices during second and third phases and simulate how the above 11 factors influenced EUA prices. The model can well compensate the shortcomings of traditional models which are not able to handle multivariate or integrate quantitative and qualitative variables. Through data mining of 1 149 groups of phase 2 data and 775 groups of phase 3 data, the study finds out the degrees of how different variables can influence EUA prices,which the descending order in phase 2 is: natural disaster > UN conferences > CER > extreme weathers > coal prices > important events > Brent oil prices > government policies > Stock600 index > natural gas prices > warm winters; the order in phase 3 changes to: UN conferences > Stock600 index > coal prices > natural disasters > extreme weathers > important events > government policies > Brent oil prices > natural gas prices > CER > warm winters. Based on further analysis,the study presents explanation of why this change happened and gives suggestions to China's future national carbon market: ①stabilize the expectation of market participants; ②improve permits offset mechanism and maintain policy consistency; ③take regional differences into account when allocate permits; ④establish emergency response mechanism of carbon rights allocation.