The internal buckling is ubiquitous in the grown CNT arrays. It is an important factor which makes the measured physical properties of carbon nanotube array further lower than that of Carbon nanotube with the perfect structure. In this work, the evolution and fabrication mechanism of the internal buckling in the vertically grown carbon nanotube arrays have been studied systematically. The formation of internal buckling of CNTs is induced due to the influence of the self-restriction effect, which is formed by the CNT terminals assembled into clusters in the top of the CNT array and the differently increase of the length of CNTs in the arrays. It makes the quasi-straight and bent CNTs coexisted in the array. Considering the interaction between CNTs, we generalized the Euler beam to wave-like beam and the model from quasi-static compression was applied to analyze buckling behavior in carbon nanotube arrays. The calculated self-restriction force of the bent CNT is about 55-60 MPa, while the maximum mean length difference of the CNTs in the arrays reaches approximately 16%. Basing on these, we have prepared the well-organized carbon nanotube array with a 300 μm thickness.