中联重科ZLJ5281JQZ20V起重机的优点有：1. 高起重能力：该起重机具有较高的起重能力，能够满足大部分重型起重工作的需求。2. 稳定性好：起重机采用了先进的稳定技术，能够保证在高空作业时的稳定性，提高工作效率和安全性。3. 操作简便：起重机配备有可调节的控制系统，操作方便，可灵活调整工作状态。4. 耐用性强：该起重机采用了高强度钢材和坚固的结构设计，能够经受长时间、高负载的工作环境，具有较强的耐用性和寿命。5. 机动性好：起重机具备较好的机动性能，能够适应复杂的工地环境，保证工作的灵活性和适应性。6. 具备安全保护系统：起重机配备有完善的安全保护系统，包括超载保护、限位保护等功能，保证起重作业的安全性。7. 技术水平高：中联重科作为国内领先的工程机械制造商，起重机采用了先进的技术和制造工艺，保证产品的品质和性能。8. 维修保养方便：起重机的构造和设计考虑了维修保养的需求，便于对设备进行维修和保养，保证设备的正常运行和使用寿命。

The advantages of Zoomlion ZLJ5281JQZ20V crane include:1. High lifting capacity: the crane has high lifting capacity, which can meet the needs of most heavy lifting work.2. Good stability: the crane adopts advanced stabilization technology, which can ensure stability when working at height, and improve the working efficiency and safety.3. Easy operation: the crane is equipped with an adjustable control system, easy to operate, can flexibly adjust the working condition. 4. strong durability: the crane adopts high-strength steel and sturdy structural design, able to withstand long time, high load working environment, with strong durability and life. 5. good mobility: the crane has good mobility, able to adapt to the complex site environment, to ensure the flexibility and adaptability of the work. 6. equipped with safety protection system: the crane is equipped with a complete safety protection system, including overload protection, limit protection and other functions, to ensure the safety of lifting operations. 7. high level of technology: Zoomlion, as a leading construction machinery manufacturer in China, the crane adopts advanced technology and manufacturing process, to ensure the quality and performance of the product. 8. easy maintenance: the construction and design of the crane take into account the need for repair and maintenance. It is convenient to repair and maintain the equipment to ensure the normal operation and service life of the equipment.