Hebrew University professors Ayelet Mizrah and Aviv Zohar jointly published the paper "Congestion Attacks in Payment Channel Networks". This paper discusses a basic loophole in payment channel networks when constructing multi-hop payments with trust. This article proposes two attack methods: the first is to lock as many high-fluidity channels as possible for a long time, and the second is to try to isolate a single node from the network and evaluate the lightning network's ability to withstand these attacks. By examining the three main implementations of Lightning Network for setting network properties and different parameters, this article proves that recent changes to Lightning Network's default parameters will make attacks more prone. The results show that by using less than 0.5 bitcoins, the liquidity of most Lightning Networks can be locked, which may damage the Lightning Network.