中文摘要：

风险投资家对多个可行的风险企业进行分阶段多期组合投资选择。基于风险投资投入资金固定、各阶段投资价值不可立即变现等特性,风险投资家控制各阶段的组合投资风险,构建了多阶段风险投资组合绝对离差优化模型,讨论了风险控制阈值变化对风险投资组合的影响。根据风险投资实际情况设计了数值例子,依据模型得出了相应的优化选择解。

英文摘要：

Venture capitalists carry out multi-stage portfolio selection in multiple feasible risk enterprises. Based on the characteristics of venture capital,such as investment value fixed and no realizable investment value immediately at the end of each stage,assuming that venture capitalists control the risk of portfolio investment in each stage,a multi-stage venture investment absolute deviation optimization model is established. The effect of risk control threshold changed on portfolio risk is discussed. According to the actual situation of venture capital,the model is applied for numerical examples getting corresponding optimization solution.