Large flat chest plus funnel chest has always been the difficult part of funnel chest treatment, and these patients are usually big children and tall. Treatment by NUSS method requires two plates, and since the pressure on the plates is extremely high due to the large sunken chest wall, the NUSS plates are mainly supported by the intercostal muscles, so it is difficult to lift the chest wall high enough to obtain good support even with two NUSS plates. Moreover, there is only one lowest point of funnel chest in general, and there are only three intercostal spaces suitable for placement of funnel chest plates, namely the third, fourth and fifth intercostal spaces (except in special cases, the sixth intercostal space is rarely used, as the sixth intercostal space corresponds to the sternum under the saber). If the first plate is placed at the lowest point, the second plate may not have space for placement. Because there must be an intercostal space between the two plates for placement, it is not easy to reach the lowest point of the funnel chest with two plates. Failure to reach the lowest point affects the correction effect on the one hand, and on the other hand, the plates tend to slide and shift. The minimally invasive funnel chest correction steel plate for large children is a wide steel plate, which is more compatible with the intercostal space of large children, and has better stability. The steel plate is erected on the two adjacent upper and lower ribs through the longitudinal fixation piece, so it can obtain the support of four ribs, and the support force is extremely strong. In this way, the whole collapsed chest wall can also be lifted by a steel plate on the lowest point of the sternal depression to obtain a perfect result. This greatly reduces surgical damage, patient pain and cost.