CircuitBreakingException when load huge data by bulk write

I got many errors like

Caused by: org.elasticsearch.common.breaker.CircuitBreakingException: [parent] Data too large, 
data for [indices:data/write/bulk[s]] would be [30897445494/28.7gb], which is larger than 
the limit of [30601641984/28.5gb], real usage: [30897441128/28.7gb], new bytes reserved: 
[4366/4.2kb], usages [request=311296/304kb, fielddata=70419/68.7kb, 
in_flight_requests=1006536/982.9kb, model_inference=0/0b, accounting=342409182/326.5mb]

,when loading huge data to 78 primary shards on 25 nodes in about 3 hours.
The index has about 73,000,000 docs and 20,000,000 docs.deleted, primary shards total size is 200GB, every node has 256GB memory.

es version: 7.12

I deploy a crontab to record _cat/nodes. It's strange that, headCurrents are about 20GB, some ramPercent is 100 when the error is happenned.

Is there anyone who can help this?