提出了一种变阶次多阶游程受限调制编码方案，在满足读出通道伺服控制及信道信噪比要求的同时，获得更好的编码效率，可以根据不同长度游程分阶时的信噪比裕量，设定不同的分阶限制条件：短游程少分阶或者不分阶，长游程多分阶。在最大限度地利用游程长度冗余的同时，降低了多阶游程造成的码间干扰影响。通过理论分析和实验测试，分析了该编码方案的特征性能，给出了该方案应用于DVD结构光盘的效果。实验结果表明，该编码方案的原始字节误码率达到了1×10-5量级，且读出信号具有良好的对称性，满足普通DVD光盘系统读出通道及伺服控制的要求。

We present a new variable multilevel run-length-limited modulation coding scheme. By using this coding scheme, better coding efficiency is obtained while the read out channel servo control and the channel signal-to-noise ratio (SNR) are met. Different phase restrictions can be set according to the SNR margin when the different run length is phased: short-run is phased less and long run is phased more. It can use the run-length redundancy to the extreme extent while reducing the inter-code interference of multi level run. Through theoretical analysis and experimental testing, the characteristics of this coding scheme are analyzed, and the performance of this scheme applied to DVD disc is also given through the test. The experimental result shows that the readout signal of the coding scheme has good symmetry with the raw byte error rate less than 1×10-5, and the coding scheme meets the requirements of the readout channel and servo control of DVD system.