In this network.if I wire voppop1 to suppress2 ,the node voppop1 can work well ,but wire it to attribute1 ,it can't work .why?

Change your Particle Radius to “Use Supplied Radius” and enter the value you want.
You can also do the same to the Effect Radius, depending on what result you are after.

Just another point, put a high value in the Particle Radius, say 2 and watch what your particles do. Very interesting. Then pipe in a Particle Fluid Surface sop below your Popnetwork sop.

thank you ,but it seems that what you said has no relationship with this question…

I want to know why the voppop1 doesn't work after it was wired to an attribute pop upstream.

it is working here exactly the same with or without attribute1 pop in stream

the one difference can be if the attribute created with attribute1 pop had exactly the same name as some parameter in voppop1
which is not the case in the file, but if the attribute was called drg1 instead of drg, then it would override drg1 parameter in voppop and it would behave differently

not sure if this is your problem or maybe you can post a file with one pop stream working and one not, to help you find the problem

thank you
Maybe the problem was caused by system.
Yesterday ,I re-opened the file. the network does work correctly.

sorry for waste your time to consider the question.