Can anyone tell me the number of soldiers in each dynasty, you can just estimate. Thanks!

Each dynasty might vary, but the average estimate of total troops for each dynasty is about 1-2 million (esp. Qin, Han, Tang, Song, Ming, Qing).

The dynasty should be able to mass at least 700,000 troops.

Right before the Sino-Japanese war of 1937-45, there were about 1.7 million troops in service. Most of them poor quality. By 1945, 3 million were in service. A year later, the number dropped to 2.6 million.