WC_Email_New_Order电子邮件由WooCommerce电子邮件系统和您的自定义代码触发。为了避免发送重复的电子邮件，您需要修改您的自定义代码。

add_action( 'email_callback', 'email_callback' ); 
function email_callback( $args ) {  
    // Check if the New Order email is enabled in WooCommerce settings
    $new_order_email_enabled = get_option( 'woocommerce_new_order_email_enabled' );
    if ( $new_order_email_enabled == 'yes' ) {
        return;
    }
    
    $email_new_order = WC()->mailer()->get_emails()['WC_Email_New_Order'];
    $email_new_order->trigger( $args['order_id'] );
}