Using Nanjing 46 japonica rice as raw material, an ideal instant soup rice product was developed by employing ultrasonic oil-assisted soaking without draining, followed by direct steaming, and rapid drying and puffing using high-speed circulating hot air. The water absorption pattern of rice by ultrasonic soaking, the amount of palm oil added on the dispersing, and the effects of soaking and steaming conditions as well as drying and puffing temperatures on the quality of instant soup rice were studied. Besides, low-field nuclear magnetic resonance imaging technique was used to visualize the moisture distribution in the rice grains under different processing conditions. The results showed that ultrasonic-assisted soaking significantly shortened the soaking time of rice. The steamed rice was easily dispersed when the mass fraction of added palm oil was not less than 1.0%, but the soup rice turned yellow when the mass fraction of palm oil exceeded 1.0%. The textural characteristics of steamed rice were well correlated with those of instant soup rice, allowing for the prediction of instant soup rice texture based on the analysis of steamed rice texture. The uniform distribution of moisture during steaming and drying was a prerequisite for moderate puffing of the rice grains and good taste after rehydration. Instant soup rice was prepared under the condition of palm oil with mass fraction 1.0%, soaking rice water ratio of 1.0∶1.2, ultrasonic soaking at room temperature for 30min, steaming at 100℃ for 30min, drying at 80℃ for 35min, and puffing at 180℃ for 25s. It could be consumed after brewing in boiling water for 5min, with a hardness value of 22.4N and a viscosity value of 3.7N, which was similar to home-made soup rice. This instant soup rice product could meet consumers' demands for traditional cuisine while adapting to modern lifestyle changes, aligning with market development trends.