三一重工SY135C（国四）挖掘机具有以下优点：1. 动力强劲：搭载了高效的动力系统，具备出色的动力输出能力，能够应对各种工作场景和复杂土地情况。2. 燃油经济性好：采用了先进的燃油系统和节能技术，能够有效降低燃油消耗量，提高工作效率。3. 操控方便：配备了人性化的操控系统，操作简单方便，能够准确、灵活地完成各种工作要求。4. 稳定性高：具备优良的抗颠翻性能，稳定的工作平台能够保证挖掘机在工作过程中的安全性和稳定性。5. 维护方便：结构合理，维修点布局合理，方便进行日常维护和保养，能够有效延长挖掘机的使用寿命。6. 外观精美：外观设计时尚美观，符合人体工学原理，提高了操作员的工作舒适度。7. 安全性高：采用了先进的安全技术和设备，加强了挖掘机在工作过程中的安全保护措施。8. 多功能性强：可以搭载多种附件和工具，实现多种工作功能，提高工作的灵活性和效率。总的来说，三一重工SY135C（国四）挖掘机具有动力强劲、燃油经济、操控方便、稳定性高、维护方便、外观精美、安全性高和多功能性强等优点。它是一台高性能的挖掘机，适用于各种工程施工和土地开垦等作业场景。

Sany SY135C (National IV) excavator has the following advantages: 1. Strong power: equipped with a highly efficient power system, with excellent power output, able to cope with a variety of work scenarios and complex land conditions. 2. Good fuel economy: the use of advanced fuel system and energy-saving technology, can effectively reduce fuel consumption and improve work efficiency. 3. Convenient manipulation: equipped with a humanized Control system, simple and convenient operation, can accurately and flexibly complete a variety of work requirements. 4. high stability: with excellent anti-subversion performance, stable working platform can ensure the safety and stability of the excavator in the work process. 5. convenient maintenance: reasonable structure, reasonable layout of the repair point, easy to carry out routine maintenance and repair, can effectively extend the service life of the excavator. 6. exquisite appearance: The appearance design is fashionable and beautiful, in line with the principle of ergonomics, which improves the operator's working comfort.7. High safety: advanced safety technology and equipment are adopted to strengthen the safety protection measures of the excavator in the working process.8. Strong multifunctionality: it can carry a variety of attachments and tools to realize a variety of working functions, which improves the flexibility and efficiency of the work. Overall, Sany SY135C (National 4) excavator has the advantages of strong power, fuel economy, easy to maneuver, high stability, easy maintenance, beautiful appearance, high safety and high versatility. It is a high-performance excavator suitable for a variety of engineering construction and land reclamation and other operating scenarios.