The invention provides a dynamic compactor construction monitoring system and a dynamic compactor construction monitoring method. The dynamic compactor construction monitoring system comprises a compacting hammer, a winding machine, a magnetoelectric encoder which is arranged on the winding machine, and a PLC which is arranged in a dynamic compactor cab; the compacting hammer is connected with oneend of a compacting hammer hook of a dynamic compactor; the winding machine is connected with the other end of the compacting hammer hook through a lifting wire rope; and the data output end of the magnetoelectric encoder is connected with the input end of the PLC. The dynamic compactor construction monitoring system and the dynamic compactor construction monitoring method have the following benefits that the dynamic compactor construction monitoring system can calculate the compacting quantity of each effective compacting of the compacting hammer of the dynamic compactor in real time, is simple in integral structure and high in measuring accuracy rate, can achieve the automatic monitoring on parameters such as the compacting hammer lifting height, the effective compacting times, the compacting hammer falling distance and the tamping settlement during the dynamic compaction construction, can provide the large-scale dynamic compaction construction with complete engineering constructiondata, and provides data guarantee for improving the engineering quality.