This is much easier if you have bought the upgrades that make your webbing stronger to hold enemies for longer, and the upgrades that make your webbing fire faster. Find six enemies together, and continue hammering until they have all been captured in the webbing. Once they have all been immobilized at once, this trophy will unlock. Be careful, as webbing an enemy to the wall will mean that this will not count.
There are lots of places to do this, for example during the Oscorp Robotics Factory level when you are faced with lots of Sentry robots at once.