With the development of science, technology and popularity of electronic transactions, quantitative investment transactions have become the focal point in the field of investment. In order to maximize returns during the investment period, we will build a single-objective PSO-based decision model based on asset price trend forecast data to develop a daily investment strategy. At first, we use price volatility as a risk factor and determine the risk level in combination with the application principle of ROC. Then, combined with the prediction results, we distinguish the gold market trading days and non-trading days, establish a single-objective programming model with the maximum daily net income as the goal. Finally, we use PSO algorithm to optimize the solution process. And we can get the daily optimal investment strategy and the final asset is $ 226648.42.