The invention discloses a method for preparing a high silicon-aluminum alloy electronic packaging material through rapid hot press. The method is characterized by comprising the following steps of: firstly mixing a gas-atomization silicon-aluminum alloy with pure aluminum powder according to a proportion to obtain a mixture with the silicon-aluminum mass ratio of (70-40):(30-60); then filling the mixture into a mould, prepressing in an argon atmosphere at a temperature of 400-500 DEG C and the pressure of 10-50 Mpa for 5-10 minutes, and then sintering at a temperature of 600-900 DEG C for 0.5-1 hour; then reducing temperature to 400-500 DEG C, and maintaining the pressure of 10-50 Mpa for 0.5-1 hour; and demoulding to obtain a silicon-aluminum alloy monolithic material with relative density of higher than 99 percent. The method can be used for preparing the silicon-aluminum alloy monolithic material which has low thermal expansion coefficient and good thermal conductivity and also simplifying the equipment, shortening the operation time, enhancing the efficiency and stabilizing the product performance.