Environmental, social and governance (ESG) issues arouse wide concern in both industry and academia to promote sustainable development. Listed companies assume the responsibility to submit annual reports to disclose their ESG outcomes genuinely. However, the challenge is that companies may overstate or slur their actual sustainable performance, and the entire ESG reporting process is hidden backward, thereby making the report untrustworthy. Accordingly, this paper proposes an architecture of smart ESG reporting platform leveraging the Internet of Things (IoT) and blockchain technologies to enable corporate crowdsensing for environmental data and enhance the security, transparency and creditability of ESG reporting process. In addition, with the aim of motivating firms to upload massive ESG raw data of high quality, we devise an incentive mechanism that grants them crypto tokens as a reputation for sustainable performance disclosure, exposed to industry and investors for reference. The maximum tokens settlement for each environmental key performance indicator (KPI) is regarded as a cooperative game for premiums, and Shapley value is applied to fairly distribute the tokens in line with the disclosure significance scored by experienced investors. Here, we take the ESG reporting guide issued by the Hong Kong exchange (HKEX) and the practice in the Hong Kong apparel industry as the context. An experimental simulation is conducted to illustrate the feasibility and effectiveness of the proposed platform architecture and approach of token allocation. This study holds the promise of providing a precedent for adopting the advanced technologies to address the greenwashing in firms and actualize intelligent and trustable ESG reporting.