A fluid pressure control device comprising: a cylinder configured to extend and contract by working fluid supplied from a pump to drive a load; a control valve configured to switch supply/discharge of the working fluid to/from the cylinder to control the extending and contracting of the cylinder; a pilot valve configured to lead pilot pressure to the control valve; a main passage configured to connect the control valve and a load-side pressure chamber of the cylinder to which load pressure acts due to the load when the control valve is in a neutral position; and a load retaining mechanism disposed on the main passage and configured to retain load pressure in the load-side pressure chamber when the control valve is in the neutral position, wherein the load retaining mechanism comprises: a check valve configured to allow the working fluid to flow only from the control valve to the load-side pressure chamber; a bypass passage configured to lead the working fluid in the load-side pressure chamber to the control valve by bypassing the check valve; and a switching valve disposed on the bypass passage and configured to switch an opened or closed state of the bypass passage, the switching valve comprises: a pilot chamber to which pilot pressure is leaded via the pilot valve; a spool configured to move in a valve-opening direction in accordance with the pilot pressure in the pilot chamber; and a biasing member configured to bias the spool in a valve-closing direction; characterized in that the switching valve includes a piston housed slidably within the pilot chamber and is configured to receive pilot pressure leaded via the pilot valve to press the spool in the valve-opening direction, a conduction path (46, 146) is configured to lead one part of a pilot pressure fluid leaded to the pilot chamber, to a drain passage, and the conduction path (46, 146) is formed in the piston and is configured to communicate with the drain passage when the piston receives pilot pressure and moves by the predetermined stroke amount or more. a cylinder configured to extend and contract by working fluid supplied from a pump to drive a load; a control valve configured to switch supply/discharge of the working fluid to/from the cylinder to control the extending and contracting of the cylinder; a pilot valve configured to lead pilot pressure to the control valve; a main passage configured to connect the control valve and a load-side pressure chamber of the cylinder to which load pressure acts due to the load when the control valve is in a neutral position; and a load retaining mechanism disposed on the main passage and configured to retain load pressure in the load-side pressure chamber when the control valve is in the neutral position, wherein the load retaining mechanism comprises: a check valve configured to allow the working fluid to flow only from the control valve to the load-side pressure chamber; a bypass passage configured to lead the working fluid in the load-side pressure chamber to the control valve by bypassing the check valve; and a switching valve disposed on the bypass passage and configured to switch an opened or closed state of the bypass passage, a check valve configured to allow the working fluid to flow only from the control valve to the load-side pressure chamber; a bypass passage configured to lead the working fluid in the load-side pressure chamber to the control valve by bypassing the check valve; and a switching valve disposed on the bypass passage and configured to switch an opened or closed state of the bypass passage, the switching valve comprises: a pilot chamber to which pilot pressure is leaded via the pilot valve; a spool configured to move in a valve-opening direction in accordance with the pilot pressure in the pilot chamber; and a biasing member configured to bias the spool in a valve-closing direction; characterized in that the switching valve includes a piston housed slidably within the pilot chamber and is configured to receive pilot pressure leaded via the pilot valve to press the spool in the valve-opening direction, a conduction path (46, 146) is configured to lead one part of a pilot pressure fluid leaded to the pilot chamber, to a drain passage, and the conduction path (46, 146) is formed in the piston and is configured to communicate with the drain passage when the piston receives pilot pressure and moves by the predetermined stroke amount or more. a pilot chamber to which pilot pressure is leaded via the pilot valve; a spool configured to move in a valve-opening direction in accordance with the pilot pressure in the pilot chamber; and a biasing member configured to bias the spool in a valve-closing direction; characterized in that the switching valve includes a piston housed slidably within the pilot chamber and is configured to receive pilot pressure leaded via the pilot valve to press the spool in the valve-opening direction, a conduction path (46, 146) is configured to lead one part of a pilot pressure fluid leaded to the pilot chamber, to a drain passage, and the conduction path (46, 146) is formed in the piston and is configured to communicate with the drain passage when the piston receives pilot pressure and moves by the predetermined stroke amount or more.