I really don’t know if the Qing Dynasty had millions of troops. Puyi has no available soldiers, I am sure of this.
The military system of the Qing Dynasty changed greatly, from Eight Banners , to Green Forest, to regiment training, to new recruits. The children of the Eight Banners were once very tough, pushing down Li Zicheng 's Chuang Army, Zhang Xianzhong 's Western Army, and Nanming various miscellaneous troops to the ground and rubbing them. But not long after the establishment of the Qing Dynasty, this hereditary system, which was far behind the society, caused the children of the Eight Banners to lose their combat effectiveness.
Of course, the combat effectiveness is no longer good, but the "Eight Banners" organization is still there. Until the end of the Qing Dynasty, the "Eight Banners" still existed. If you don't believe it, read Lao She's novels and autobiography and you will know: Lao She's father was a flag soldier and died in battle when the Eight-Power Allied Forces entered Beijing.
Green Forest Camp was reorganized from the Ming army and other Han armies that were collected in the early years of Shunzhi. The Green Forest Army played an important role in the early Qing Dynasty in pacifying the San Francisco and other wars. However, after the middle of the Qing Dynasty, the camp operations were depleted and became increasingly corrupt. When suppressing the Taiping Army, they basically suffered repeated defeats. As a result, they were eliminated from Tongzhi to Guangxu, and gradually only had an empty name.
Because the Eight Banners and Green Forest were unavailable, the Qing government had no choice but to use local armed forces. The Hunan Army , Huai Army and others made great contributions in suppressing the Taiping Heavenly Kingdom . Local powerful factions also took the opportunity to gain power. By the time Empress declared war on the Eight-Power Allied Forces, these local powerful factions had dared to engage in " Southeast Mutual Protection " and were actually out of control of the central government.
In order to strengthen the army, the Qing government sent Zhang Zhidong, Wen Chudao, Yuan Shikai and others to train the last regular army with combat effectiveness. Because this army completely uses Western-style military systems, training and equipment, it is called the "New Army".
Speaking of this, the question on the title also has an answer: the last regular army with combat effectiveness in the Qing Dynasty was the New Army. Yuan Shikai was the leader of the New Army, and it was the New Army that first revolted in Wuchang. Shaanxi, Hunan, Jiangxi, Anhui... and other places that responded to the Wuchang Uprising were also New Army uprisings. Except for the uprisings of the civilian army and business groups in Shanghai and Guangdong and Guangxi, the Revolution of 1911 was basically a major uprising of the new armies in various places.
There was still an army in the Qing Dynasty, so why did Puyi abdicate? Because it was the Qing army that overthrew the Qing Dynasty.
