rails g migration add_slug_to_pages slug:string
rails g friendly_id
bunlde exec rake db:migrate
rails c
Page.find_each(&:save)

# config/initializers/friendly_id/slugged.rb
module FriendlyId
module Slugged
  def normalize_friendly_id(value)
    Pinyin.t(value.to_s).parameterize
  end
end
end

class AddSlugToPages < ActiveRecord::Migration
  def change
    add_column :pages, :slug, :string
    add_index :pages, :slug
  end
end

class CreateFriendlyIdSlugs < ActiveRecord::Migration
  def change
    create_table :friendly_id_slugs do |t|
      t.string   :slug,           :null => false
      t.integer  :sluggable_id,   :null => false
      t.string   :sluggable_type, :limit => 50
      t.string   :scope
      t.datetime :created_at
    end
    add_index :friendly_id_slugs, :sluggable_id
    add_index :friendly_id_slugs, [:slug, :sluggable_type], length: { slug: 140, sluggable_type: 50 }
    add_index :friendly_id_slugs, [:slug, :sluggable_type, :scope], length: { slug: 70, sluggable_type: 50, scope: 70 }, unique: true
    add_index :friendly_id_slugs, :sluggable_type
  end
end

#page.rb
class Page < ActiveRecord::Base
extend FriendlyId
    friendly_id :title, use: :slugged
    def should_generate_new_friendly_id?
      new_record? || slug.blank?
    end
end

#pages_controller.rb
class PagesController < ApplicationController
    def set_page
    @page = Page.friendly.find(params[:id])
    redirect_to action: [:edit,:show,:update,:destroy], id: @page.friendly_id, status: 301 unless @page.friendly_id == params[:id]
    end
end