In the new era of rapid development of science and technology, the combination of finance and technology has brought new financial cognition to people, but the emergence of financial technology has also brought great challenges to risk management in the financial field. With the development and maturity of Internet technology, the rapid innovation of Internet finance has promoted the prosperity of online lending, well met the financing needs of various entities in the market, and effectively solved the problem of expensive financing for small and medium-sized enterprises and private enterprises. However, the rapid development of Internet finance has also spawned a wider range of financial risks and updated forms. Taking P2P online lending as an example, this paper analyzes the causes and effects of the rise of P2P online lending, finds that there is asymmetric leverage effect in the fluctuations of P2P online lending, analyzes the risks, existing problems and causes of final failure of P2P online lending, and explores the development model of online lending in the post-P2P era and the construction of big data risk control system. Finally, some practical suggestions and countermeasures are given.