Abstract: Sand plug is one of the important reasons for failure of hydraulic fracturing, and for this purpose, a set of real-time monitoring and warning system for hydraulic fracturing has been developed. Based on real-time monitoring of key fracturing parameters, this system realizes real-time warning for hydraulic fracturing through double-log slopes of tubing pressure-time and casing pressure –time curves. Based on the analysis of fracturing data from a number of wells, three modes of pressure-time double-log curves were analyzed, so by real-time determining which mode the current fracturing status is in, then the risk which may occur in such mode can be forecasted. Also, according to matured 2D fracture models PKN and KGD as well as Penny radial model, the fracture length and average width can be calculated, which can be used to determine whether the fracture orientation is in compliance with the design. In case of deviation, then dynamic parameters may be reduced to change the fracture orientation. The field application result shows that this system integrates real-time monitoring of data and early warning and is of good application value.