He usually is having lunch now哪错了

usually是通常的
你用的是现在时态
矛盾了

去掉usually就好了

语序错误+语法错误
usually是通常的
你用的是现在时态

你的意思是他经常在这个时候吃饭么？
如果是这样，不改变原来的意思就是：
He usually has lunch at this time of the day.

he usually has lunch at this time. 他通常这个时候吃午饭。

usually 通常，不能用进行时态

指每一天的特定时间，不用now，用at this time。

如果说他正在吃午饭he is having lunch now.

usually是频度副词，一般用于一般时，不用于进行时。
应改为：He is having lunch now。
usually用法如：He usually goes to school on foot.(一般现在时)

He usually has lunch at that time
He is having lunch now

首先usually是一个频率副词，不可表示正在做某事。（因为有now）
有几种改法，1.As usual, he is having lunch now.
2.he is having lunch now，as usual.
3.He is having lunch now
4.He usually has lunch