徐工QY70KC起重机的优点有：1. 强大的起重能力：徐工QY70KC起重机具有70吨的起重能力，能够满足大部分起重需求。2. 灵活性好：起重机采用了全新的设计理念，具有旋转性能和便携性，可在狭小的工地上进行起重作业。3. 安全性高：起重机配备了先进的安全系统，如安全锁、过载保护和防倾翻装置，能够确保起重作业的安全性。4. 操控方便：起重机采用了先进的液压系统和电子操控系统，操纵简单方便，操作者可以轻松掌握。5. 质量可靠：徐工QY70KC起重机选用高品质的材料和部件，经过严格的质量控制，具有持久性和可靠性。6. 维护成本低：起重机的设计合理，易于维护和保养，能够减少维修成本和停机时间。总之，徐工QY70KC起重机具有起重能力强大、灵活性好、安全性高、操控方便、质量可靠和维护成本低等优点，适用于各种起重作业的需求。

The advantages of XCMG QY70KC crane are: 1. powerful lifting capacity: XCMG QY70KC crane has a lifting capacity of 70 tons, which is able to meet most of the lifting needs. 2. good flexibility: the crane adopts a new design concept with rotary performance and portability, which can be used for lifting operations in narrow construction sites. 3. high safety: the crane is equipped with advanced safety systems, such as safety lock, overload protection and anti-tipping device, which can ensure the safety of lifting operations.4. Convenient manipulation: The crane adopts advanced hydraulic system and electronic control system, which is simple and convenient to manipulate, and the operator can easily master it.5. Reliable quality: XCMG QY70KC cranes are made of high-quality materials and components, which are subject to stringent quality control, and have durability and reliability.6. Low maintenance cost : The cranes are well-designed and easy to maintain and service, which can reduce the maintenance cost and downtime. In a word, XCMG QY70KC cranes have the advantages of powerful lifting capacity, good flexibility, high safety, easy maneuverability, reliable quality and low maintenance cost, which are suitable for all kinds of lifting operation needs.