Session-Based Recommendation (SBR) is to predict next item, given an anonymous interaction sequence. Recently, many advanced SBR models show great recommending performance, but few studies note that they suffer from popularity bias seriously: the model tends to recommend popular items and fails to recommend longtail items. The only few debias works relieve popularity bias indeed. However, they ignore individual's conformity towards popular items and thus decrease recommending performance on popular items. Besides, conformity is always entangled with individual's real interest, which hinders extracting one's comprehensive preference. To tackle the problem, we propose a SBR framework with Disentangling InteRest And Conformity (DIRAC) for eliminating popularity bias in SBR. In this framework, two group of item encoders and session modeling modules are devised to extract interest and conformity respectively, and a fusion module is designed to combine these two types of preference. Also, a discrepancy loss is utilized to disentangle representation of interest and conformity. Besides, our devised framework can integrate with several SBR models seamlessly. We conduct extensive experiments on two real-world datasets with three advanced SBR models. The results show that our framework outperforms other state-of-art debias methods consistently. Disentangling Interest and Conformity for... Fig. 1 An illustration of popularity bias in SBR. Items are grouped by their popularity in Diginetica dataset, which is commonly used in SBR experiment. Popularity is defined as the number of interaction of one item in dataset. The vertical axis represents mean reciprocal rank of SR-GNN and corresponding debias methods. The histogram shows the number of items in each item group.