longtable环境下表格无法跨页问题

\documentclass{article}
\usepackage{longtable}
\usepackage[table]{xcolor}
\begin{document}
    We put the data of 42 monitoring points of each person into the training model and record their weights respectively. The top 15 weights with the highest contribution rate were selected. Then we make up 25 features which can affect the body's balance by using the seweights.

    \newcommand{\tabincell}[2]{\begin{tabular}{@{}#1@{}}#2\end{tabular}}  
    \begin{table}[h]
        \centering
        \caption{Composition Analysis of Equilibrium Characteristic}
        \begin{longtable}{|c|c|c|p{8cm}<{\centering}|}
            \hline
            & \textbf{Balance features} & \textbf{Monitoring points} & \textbf{Description}\\
            \hline
            1&Step length&36,37&\tabincell{l}{length means that the distance between one side \\of the foot following the ground and the next\\ side\ following the ground, have individual\\ difference, basically concern with the mobile\\range of leg length, hip joint and knee joint, \\have the cent of right and left lower limbs}\\
            \hline
            2&Stride length&34,35,36,37&\tabincell{l}{In one step cycle, the distance from the \\coordinate position of a unilateral foot print to \\the forward and back ward direction of the next \\foot print on the same side}\\
            \hline
            3&Step width&34,35,36,37&\tabincell{l}{Step width refers to the distance between the \\center linesof the feet on both sides in walking.\\The calculation method isthe distance from the \\center of the foot print on one side to the center \\of the footprint on the opposite side along the X-\\axis in a gait cycle}\\
            \hline
            4&Step speed&34,35,36,37&\tabincell{l}{Step speed refers to the distance traveled per unit\\ of time, which measures the speed of walking.\\The test method is to measure the distance \\travele\ and the time by the footpath, and then\\ calculate the ratio}\\
            \hline
            5&Left support phase&35,37&\tabincell{l}{The left supporting phase is the time when the \\left lower limb contacts the ground in a gait \\cycle. The calculation method is that the time \\when the left lower limb leaves the ground at the \\NTH step minus the time when the left lower \\limb lands
            }\\
            \hline
            6&Oscillating phase&35,37&\tabincell{l}{Swing refers to the period of time in which a \\single lower limb swings in the air in a gait cycle.\\ The calculation method is that the moment of \\landing of a single lower limb minus the moment\\ of leaving the ground of the previous step
            }\\
            \hline
        \end{longtable}
    \end{table}
\end{document}