作为一种创新型衍生金融投资工具，私募股权投资基金能够优化资源配置、促进资金合理流通，从而对社会经济的发展带来了一定的积极作用，但由于金融市场波动的不规则性、经济下行压力以及投资环境有待改善等等不可控因素的存在，使得私募股权基金在投资过程中潜藏着巨大的风险，因此，对私募股权投资风险进行有效的预测具有重要意义。基于此，本文提出了相似度加权投票组合的方法来构建私募股权投资风险预测模型，在知识引导决策的基础上，结合近邻混合案例检索决策规则的优点，提出了最大化相似度加权投票概率决策准则，并将模型参数设定在经验取值范围内，使得模型能够对待预测投资案例的风险状况进行有效的分类，实证仿真结果也证明了该方法的可靠性和有效性。

As an innovative financial derivatives instruments ,Private equity investment funds can optimize the allocation of resources、promote the rational flow of funds and bring a positive effect on the social and economic development. But because of the irregularity of financial market volatility、economic downward pressure and the exit of many uncertain factors of improving investment environment，Making private equity fund lurking in the process of investment risks，Therefore，an effective prediction for private equity investment risk is of great significance. Based on this, Similarity Weighted Voting Combination is proposed in this paper to build private equity investment risk prediction model，On the basis of knowledge to guide the decision combining the advantages of nearest neighbor mixed case retrieval of decision rules，Putting forward the maximum similarity weighted voting probabilistic decision rules and setting the model parameters in the range of experience value，which makes model effective classification for predicting the risk of our investment case，The empirical simulation results also prove the reliability and effectiveness of the proposed method.