中联重科ZTC121V451起重机的优点有：1. 高效性能：该起重机具备较高的起重效率和作业能力，能够快速完成各类起重作业任务，提高工作效率。2. 稳定可靠：该起重机采用先进的技术和设计，具备较好的稳定性和可靠性，能够在各种恶劣工作环境下正常运行，确保作业安全。3. 灵活机动：该起重机具备较小的转弯半径和灵活的工作机构，能够适应狭小空间和复杂工况，实现各种复杂作业要求。4. 操作方便：该起重机配备先进的人机工程学控制系统和操作界面，操作简单、易学易懂，提高了工作人员的操作效率和操作安全性。5. 维护便捷：该起重机的维护保养工作较为方便，维修时间较短，能够减少设备的停机时间，提高作业效率。6. 节能环保：该起重机采用先进的动力系统和节能技术，能够降低能耗和排放，符合环保要求，减少对环境的影响。

Advantages of Zoomlion ZTC121V451 crane are: 1. High efficiency performance: the crane has a high lifting efficiency and operating capacity, can quickly complete all kinds of lifting tasks, improve work efficiency. 2. Stable and reliable: the crane adopts the advanced technology and design, with good stability and reliability, can be in a variety of poor working environment normal operation, to ensure operational safety. 3. flexible and mobile: the crane is equipped with a small turning radius and flexible working mechanism to adapt to the narrow space and complex working conditions. 4. Flexible: the crane has a small turning radius and flexible working mechanism, can adapt to the narrow space and complex working conditions, to achieve a variety of complex operational requirements. 4. easy to operate: the crane is equipped with advanced ergonomic control system and operator interface, simple operation, easy to learn and easy to understand, to improve the staff's operational efficiency and operational safety. 5. convenient maintenance: the crane's maintenance Convenient maintenance: the crane's maintenance is more convenient and the maintenance time is shorter, which can reduce the downtime of the equipment and improve the operational efficiency. 6. energy saving and environmental protection: the crane adopts advanced power system and energy saving technology, which can reduce the energy consumption and emissions, comply with the environmental protection requirements, and reduce the impact on the environment.