I look at how investors can use insurance market stocks to make a profit and reduce risk by increasing their investments in high-tech agricultural types of counter-cyclical industries. By comparing the correlation coefficient between the two companies, the investment target is determined, and then the scatter diagram is drawn to observe the distribution of the random portfolio. Then,the optimal portfolio is obtained by studying the efficient boundary on the scatter diagram and the Sharpe ratio in various special cases. Through these analyses, I found that the portfolio on the effective frontier is the maximum return at the corresponding risk or the minimum risk at the corresponding return. Moreover, investors can determine the best portfolio by calculating the maximum Sharpe ratio, and the portfolio corresponding to the maximum Sharpe ratio is also on the efficient frontier. This research has great significance in real life. It can let people not limited to the pure investment insurance business, but try to hold insurance company shares for a long period to get profit.