How to Display all product in Woocommerce

Just make the below changes and set the option ‘posts_per_page’ to ‘-1’.

Open file class-wc-query.php

And make the below edits.

Comment the below line
//$q->set( 'posts_per_page', $q->get( 'posts_per_page' ) ? $q->get( 'posts_per_page' ) : apply_filters( 'loop_shop_per_page', get_option( 'posts_per_page' ) ) );

And replace by
$q->set( 'posts_per_page', '-1');